Journal articles on the topic 'Single-crystal Cu-Al-Be'
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1
Xu, Hua Ping, Hui Hu, Gao Feng Song, Chong He Li, and Xie Min Mao. "Behavior and Preparation of Single Crystal of Cu-Al-Ni-Be SMA." Materials Science Forum 561-565 (October 2007): 1463–66. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.1463.
Abstract:
In this paper, single crystal of CuAlNiBe shape memory alloy (SMA) was prepared in a high temperature gradient directional solidification furnace with a selective growing crystallizer. And its performance characters were systematically studied. The results show that the mechanical and shape memory properties of the single crystal of CuAlNiBe SMA alloy has much better than that of the polycrystalline material. This may be explained that the stress concentration at grain boundary caused by the difference of bilateral strains is the dominant reason of deterioration of fatigue properties; therefore single crystal alloy possesses the excellent properties duo to its elimination of grain boundary.
2
Xu, Hua Ping, Gao Feng Song, and Xie Min Mao. "Influence of Be and Ni to Cu-Al Alloy Shape Memory Performance." Advanced Materials Research 197-198 (February 2011): 1258–62. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.1258.
Abstract:
With Bridgeman directional solidification method the single crystal alloys of CuAl base shape memory alloy (SMA) with different components were prepared. And their shape memory performance characters were systematically investigated. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has much better shape memory properties than that of the CuAlBe and CuAlNi ternary alloy. That meant that in the CuAl base SMA alloy the mixed addition of Be and Ni changed the quenching microstructure has a strengthening effect to improve the shape memory performance of the SMA alloy.
3
Siredey, N., A. Hautcoeur, and A. Eberhardt. "Lifetime of superelastic Cu–Al–Be single crystal wires under bending fatigue." Materials Science and Engineering: A 396, no. 1-2 (April 2005): 296–301. http://dx.doi.org/10.1016/j.msea.2005.01.021.
4
Xu, Hua Ping, Gao Feng Song, and Xie Min Mao. "A Study on Shape Memory Performance of Cu-Al-Ni-Be Alloy Single Crystal." Advanced Materials Research 287-290 (July 2011): 21–25. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.21.
Abstract:
In this paper, single crystal of CuAlNiBe quaternary shape memory alloy was prepared in a high temperature gradient directional solidification furnace with a selective growing crystallizer. And its shape memory performance characters were systematically compared with other series copper base shape memory alloys. The results show that the single crystal of CuAlNiBe quaternary shape memory alloy has better shape memory properties.
5
Gonzalez, C. H., C. J. De Araújo, N. F. Quadros, G. Guénin, and M. Morin. "Study of martensitic stabilisation under stress in Cu–Al–Be shape memory alloy single crystal." Materials Science and Engineering: A 378, no. 1-2 (July 2004): 253–56. http://dx.doi.org/10.1016/j.msea.2003.11.069.
6
Пульнев, С. А., А. И. Прядко, А. В. Чикиряка, and В. И. Николаев. "Эффект локализации деформации в монокристаллах Cu-Al-Ni при изгибе продольной силой." Письма в журнал технической физики 44, no. 21 (2018): 91. http://dx.doi.org/10.21883/pjtf.2018.21.46860.17425.
Abstract:
AbstractThe behavior of a superelastic Cu−14.2% Al−4%Ni single crystal in the case of high reversible strains under a longitudinal bending force was investigated. The effect of strain confinement along the crystal length was revealed and studied. The highest reversible strains (up to 10%) were shown to be confined within the central part of the bent crystal.
7
Kortan, A. R., H. S. Chen, and J. V. Waszczak. "Single-crystal x-ray diffraction from an icosahedral quasicrystal." Journal of Materials Research 2, no. 3 (June 1987): 294–97. http://dx.doi.org/10.1557/jmr.1987.0294.
Abstract:
Single-crystal x-ray diffraction measurements made on a millimeter-size single icosahedral quasicrystal of an Al–Li–Cu alloy are reported. The point symmetries observed directly by real-time transmission Laue x-ray diffraction and the measured angles between the major symmetry axis are consistent with an icosahedral quasicrystal, and the peaks observed in the single-crystal diffraction scans are found to be indexable with six indices that belong to a primitive icosahedral Bravais quasilattice.
8
Siredey-Schwaller, N., A. Eberhardt, and P. Bastie. "Parameters influencing the fatigue life of a Cu–Al–Be single-crystal shape memory alloy under repeated bending." Smart Materials and Structures 18, no. 2 (January 22, 2009): 025014. http://dx.doi.org/10.1088/0964-1726/18/2/025014.
9
Ho, Ching Hwa, Chia Chi Pan, Jian Rong Cai, Guan Tzu Huang, Dumitru O. Dumcenco, Ying Sheng Huang, Kwong Kau Tiong, and Ching Cherng Wu. "Structural and Band-Edge Properties of Cu(AlxIn1-X)S2 (0≤x≤1) Series Chalcopyrite Semiconductors." Solid State Phenomena 194 (November 2012): 133–38. http://dx.doi.org/10.4028/www.scientific.net/ssp.194.133.
Abstract:
We have demonstrated structural and electronic properties of a series solar energy crystals Cu(AlxIn1-x)S2 (0<=x<=1) by using measurement techniques of X-ray diffraction, polarized thermoreflectance (PTR), and X-ray photoelectron spectroscopy (XPS). Single crystals of Cu(AlxIn1-x)S2 (0<=x<=1) (0 and E ^ polarizations. The PTR spectra clearly showed that the energy value of D increases with the increase of Al content x in the Cu(AlxIn1-x)S2 (0<=x<=1) series due to the enhanced strain in the lattice. The composition-dependent crystal-field-splitting energies can be evaluated and determined to be D(x)= (10±2)+( 139±5)×x meV. Based on the experimental analyses, the crystal structure and valence-band structure of the Cu(AlxIn1-x)S2 (0<=x<=1) (0<=x<=1) series are thus realized.
10
Pavlyuk, Nazar, Grygoriy Dmytriv, Volodymyr Pavlyuk, and Helmut Ehrenberg. "Li20Mg6Cu13Al42: a new ordered quaternary superstructure to the icosahedral T-Mg32(Zn,Al)49 phase with fullerene-like Al60 cluster." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, no. 2 (March 16, 2019): 168–74. http://dx.doi.org/10.1107/s2052520619000349.
Abstract:
The new quaternary aluminide Li20Mg6Cu13Al42 was synthesized from the elements in a sealed tantalum crucible. The crystal structure was studied by single crystal and confirmed by X-ray powder diffraction. Li20Mg6Cu13Al42 {cI162, Im{\overline 3}, a = 13.8451 (2), R[F 2 > 2σ(F 2)] = 0.023} crystallizes as an ordered version of Mg32(Al,Zn)49 and Li—Cu—X (X = Al, Ga, Si) periodic crystals containing icosahedral clusters. The Li20Mg6Cu13Al42 structure can also be described as three-shell icosahedral clusters of [CuAl12@Li20Cu12@Al60], enclosed inside a distorted triacontahedron. The electronic structure calculations were performed by means of the TB-LMTO-ASA program and confirm the core–shell packing of these clusters. The isostructural compound of Li20Mg6Cu13Ga42 was found in a Li–Mg–Cu–Ga quaternary system.
11
Krawczyk, Jacek, Wojciech Gurdziel, Włodzimierz Bogdanowicz, and Krzysztof Flisiński. "Temperature Influence on Stress-Strain Relationship of Al-Cu-Fe Crystal-Quasicrystal Composites." Solid State Phenomena 163 (June 2010): 282–85. http://dx.doi.org/10.4028/www.scientific.net/ssp.163.282.
Abstract:
The columnar composites obtained “in situ” through solidification of Al61Cu27Fe12 alloy by the Bridgman method were studied. It has been verified that the matrix consisted of cubic single crystal β phase and the reinforcement of icosahedral quasicrystal ψ phase and monoclinic crystal λ phase, which have the form of rods. This kind of composites will be named the Al-Cu-Fe crystal-quasicrystal (CQ) composites. The effect of heating from a temperature of about 100°C to about 650°C on the stress-strain relationships σ(ε) of parallel samples was studied. Additionally, the σ(ε) relationship was defined in cyclic load-unload tests at different temperatures. The composites were examined by powder X-ray diffraction and scanning electron microscope.
12
Tokarski, Tomasz, Grzegorz Cios, Dorota Moszczynska, Boguslawa Adamczyk-Cieslak, Milena Koralnik, and Jaroslaw Mizera. "Texture Evolution of a Single Crystal Cu-8% at. Al Subjected to the Drawing Process." Crystals 12, no. 10 (October 11, 2022): 1435. http://dx.doi.org/10.3390/cryst12101435.
Abstract:
Single crystals of Cu-8.% at. Al were subjected to cold drawing up to 1.1 true strain. Development of the crystallographic texture was analysed at various stages of the drawing process. Investigations revealed significant crystal rotation and reorientation due to a twinning process, while general 4-fold symmetry around the drawing direction was preserved. Local texture analysis performed on cross-sections perpendicular to the drawing direction showed that due to crystal rotation, the original crystal was initially fragmented into four quadrants. However, within the volume near the central axis the initial cubic orientation was preserved. Subsequent deformation within dominating twinning systems led to further fragmentation which divided the crystal into sectors one eighth the size of the full circular cross-section. The obtained results also indicate that approximation of the drawing process stress state by the tensor having only normal components cannot be used during analysis of the activation of deformation systems.
13
Kuczera, Pawel, Janusz Wolny, and Walter Steurer. "Comparative structural study of decagonal quasicrystals in the systems Al–Cu–Me (Me = Co, Rh, Ir)." Acta Crystallographica Section B Structural Science 68, no. 6 (November 16, 2012): 578–89. http://dx.doi.org/10.1107/s0108768112041134.
Abstract:
A comparative single-crystal X-ray diffraction structure analysis of the family of Al–Cu–Me (Me = Co, Rh and Ir) decagonal quasicrystals is presented. In contrast to decagonal Al–Cu–Co, the other two decagonal phases do not show any structured disorder diffuse scattering indicating a higher degree of order. Furthermore, the atomic sites of Rh and Ir can be clearly identified, while Cu and Co cannot be distinguished because of their too similar atomic scattering factors. The structure models, derived from charge-flipping/low-density elimination results, were refined within the tiling-decoration method but also discussed in the five-dimensional embedding approach. The basic structural building units of the closely related structures are decagonal clusters with 33 Å diameter, which are consistent with the available electron-microscopic images. The refined structure models agree very well with the experimental data.
14
Castillo, Fernando Néstor García, Rafael Schouwenaars, Jacinto Cortés Pérez, Vicente Amigó Borrás, and Miguel Ángel Ramírez Toledo. "ANALYSIS OF THE MARTENSITE VARIANT SELECTION IN A SINGLE CRYSTAL CU-AL-BE SHAPE MEMORY ALLOY IN A TENSILE TEST." Journal of Engineering Research 2, no. 12 (June 30, 2022): 2–11. http://dx.doi.org/10.22533/at.ed.3172122230067.
15
Adamo, I., G. D. Gatta, N. Rotiroti, V. Diella, and A. Pavese. "Gemmological investigation of a synthetic blue beryl: a multi-methodological study." Mineralogical Magazine 72, no. 3 (June 2008): 799–808. http://dx.doi.org/10.1180/minmag.2008.072.3.799.
Abstract:
AbstractA multi-methodological investigation of a synthetic Cu/Fe-bearing blue beryl [IV(Be2.86Cu0.14)∑=3.00VI(Al1.83Fe3+0.14Mn2+0.03Mg0.03)∑=2.03IV(Si5.97Al0.03∑=6.00O18.(Li0.12Na0.04.0.40H2O)] has been performed by means of gemmological standard testing, electron microprobe chemical analyses, laser ablation inductively coupled plasma mass spectroscopy, thermo-gravimetric analyses, infrared spectroscopy and single-crystal X-ray diffraction in order to determine the gemmological properties, crystal structure and crystal-chemistry of this material. The increasing production of marketable hydrothermal synthetic beryls with 'exotic' colours and the small number of studies on the accurate location of chromophores in the crystal structure inspired this multi-methodological investigation. The X-ray structural refinements confirm that the space group of the Cu/Fe-bearing blue beryl is P6/mcc, with unit-cell parameters: 9.2483 ≤ a ≤ 9.2502 Å and 9.2184 ≤ c ≤ 9.2211 Å. The analysis of the difference Fourier maps of the electron density suggests that Cu is located at the tetrahedral site (Wyckoff 6fposition) along with Be, whereas Fe shares the octahedral site with Al (4c position). No evidence of extra-framework Cu/Fe-sites (i.e. channel sites) has been found. The Li is probably located at the extra-framework 2b site. Infrared spectra show that the H2O molecules are present with two configurations: one with the H···H vector oriented ‖[0001] and the other with H···H vector oriented ⊥[0001].
16
Schaper, Jacob A. "Imaging and analysis of submicron single-crystal aluminum whiskers in Al/Cu/Si deposited films." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1290–91. http://dx.doi.org/10.1017/s0424820100131085.
Abstract:
The formation of stress-relieving hillocks, also referred to as single-crystal whiskers is a well-known occurrence in the preparation of metallic thin films. In the manufacture of Application Specific Integrated Circuits, devices at the wafer level are often processed through the first metallic thin film process, coated with a plasma enhanced oxide (PEO), then stockpiled either at the manufacturer's site or the customer's to await final option-level programming. Whisker growth has been detected on wafers retrieved from the stockpile inventory. This paper describes the techniques employed for initial detection, subsequent sample preparation, and the composition analysis of submicron diameter whiskers in Al/Cu/Si thin films on inventoried product wafers.First indications of whisker growth are increased surface defect levels observed during high power optical microscope sample inspection. Typical appearance of the whiskers, as viewed with an optical microscope, are shown in Figure 1. Structures thought to be surface particles are later imaged in the SEM and confirmed to be oxide-covered whiskers, as shown in Figure 2. Imaging of the nonconductive oxide layer is accomplished via a Field Emission SEM.
17
Ren, Wei Min, Zi Yong Chen, Zhi Lei Xiang, and Li Hua Chai. "Microstructure and Properties of Rapidly Solidified Al-Zn-Mg-Cu Alloy." Materials Science Forum 993 (May 2020): 203–7. http://dx.doi.org/10.4028/www.scientific.net/msf.993.203.
Abstract:
Refining grain plays an important role in improving the mechanical properties of aluminum alloys. However, the conventional casting method with a slow cooling rate can be easy to cause coarseness of the microstructure and serious segregation. In this paper, the rapid solidification of Al-Zn-Mg-Cu alloy was prepared by the single-roller belt method. The alloy strip was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness test to study the microstructure and properties of the rapidly solidified aluminum alloy. The results show that the roller speed was an important parameters affecting the formability of the alloy. When the roller speed was 15 m/s, the aluminum alloy produced a thin bandwidth of 5 mm and a thickness of 150 um. As the rotation speed of the roller increased, the cooling rate of the melt increased, and the microstructure of the rapidly solidified Al-Zn-Mg-Cu aluminum alloy strip improved in grains refinement. Compared with the conventionally cast Al-Zn-Mg-Cu aluminum alloys, the Al-Zn-Mg-Cu aluminum alloys prepared by rapid solidification showed much finer crystal grains, and enhanced solid solubility of alloying elements with less precipitation of second phase and high hardness.
18
Ramani, Atul S., Lucille A. Giannuzzi, Altaf H. Carim, William R. Bitler, and Paul R. Howell. "New phases in the Al-Co-Cu alloy system : Marked variations from the “true” decagonal phase." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 32–33. http://dx.doi.org/10.1017/s0424820100120564.
Abstract:
The decagonal phase in the Al-Co-Cu alloy system was first discovered by He et al. We shall call this phase the “true” decagonal phase (TD) phase because it is the one most commonly observed in the Al-Co-Cu alloy system. It is well known that quasicrystalline phases such as the TD phase contain the phason defect peculiar to incommensurate phases that causes subtle variations from perfect decagonal symmetry. In this paper we report on the existence of new phases in the Al-Co-Cu alloy system, that are related to the TD phase but yet show marked variations from the TD phase. These variations are too drastic to be caused by phason defects alone.Figure 1(a) is a selected area diffraction pattern (SADP) recorded from a TD phase single “crystal” showing near perfect decagonal (tenfold) symmetry. This SADP agrees very well with the first published SADP of the TD phase in Al-Co-Cu that also shows almost perfect decagonal symmetry. In a previous paper we have reported several kinds of deviations from perfect decagonal symmetry, but none of these deviations involved the observation of perfect pentagonal (fivefold) symmetry. Figure 1(b) is an SADP recorded from a phase in Al-Co-Cu that exhibits perfect pentagonal symmetry instead of the expected decagonal symmetry. This breakdown of true tenfold symmetry into true fivefold symmetry is caused by unequal intensities of equal and opposite reflections. This example is a clear violation of Friedel's law, which states that the intensities of equal and opposite diffraction vectors must be equal.
19
MAÑOSA, LLUÍS, ANTONI PLANES, EDUARD VIVES, ERELL BONNOT, and RICARDO ROMERO. "THE USE OF SHAPE-MEMORY ALLOYS FOR MECHANICAL REFRIGERATION." Functional Materials Letters 02, no. 02 (June 2009): 73–78. http://dx.doi.org/10.1142/s1793604709000594.
Abstract:
This letter reports on stress–strain experiments on a Cu – Zn – Al single crystal performed using a purpose-built tensile device which enables the load applied to the specimen to be controlled while elongation is continuously monitored. From the measured isothermal tensile curves, the stress-induced entropy changes are obtained at different temperatures. These data quantify the elastocaloric effect associated with the martensitic transition in shape-memory alloys. The large temperature changes estimated for this effect, suggest the possibility of using shape-memory alloys as mechanical refrigerators.
20
Motoyama, Munekazu, Katsutoshi Sakurai, Hisao Kiuchi, Tomotaka Nakatani, Takashi Nakagawa, Yasutoshi Iriyama, Zempachi Ogumi, and Takeshi Abe. "(Invited) Effects of the Alloy Composition on Cycling Performance of Cu-Ni Alloy Cathodes in All-Solid-State-Fluoride-Shuttle Batteries." ECS Meeting Abstracts MA2022-02, no. 47 (October 9, 2022): 1734. http://dx.doi.org/10.1149/ma2022-02471734mtgabs.
Abstract:
Metal fluorides generally have low electric conductivities. Hence, if a single metal (e.g. Cu) is used as the cathode active material for a fluoride-shuttle battery (FSB), the electric resistance in the cathode increases after the fluoridation reaction (charging).1,2 Hence, repeating charging and discharging leads to significant drop in capacity. If an alloy consisting of two metal elements with different fluorination/defluorination potentials is used as the cathode active material, one metal element behaves as a conductive metal even when the other metal element is fluorinated, and the increase in electric resistance can be suppressed. So, we evaluated Cu-Ni binary alloys as cathode active materials for FSB in this study. The standard redox potentials (25 °C) of NiF2/Ni and CuF2/Cu are +0.11 V and +0.72 V (vs. PbF2/Pb), respectively. 3 Although NiF2 is an insulating compound, Cu behaves as a metal, providing electron conduction pathways. Additionally, the crystal structures of Cu and Ni are commonly fcc structures, with lattice constants of 3.597 Å and 3.499 Å, respectively, so that Cu-Ni alloys exhibit solid solutions in the full composition range above 380 °C in the phase diagram. Hence, the Cu-Ni alloy is considered to be an ideal alloy system that hardly separates different phases and can provide highly-dense-interconnecting-electron-conduction pathways within the whole cathode like veins. Cu x Ni1−x (x = 0, 0.3, 0.5, 0.7, 1.0) films with thicknesses of approximately 3 nm were sputter-deposited onto 0.5-mm-thick LaF3 solid electrolytes to form all-solid-state PbF2/LaF3/Cu x Ni1−x cells. Charging/discharging curves and Nyquist plots of the cells were measured under high vacuum (< 10−3 Pa) at 140 °C. Acknowledgment This paper is based on the results obtained from projects, JPNP16001 and JPNP21006, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References Okazaki et al., ACS Energy Lett., 2, 1460 (2017). Yamamoto et al., ACS Appl. Energy Mater. , 2, 6153 (2019). Gschwind et al., J. Fluor. Chem., 182, 76 (2016).
21
Krasnikov, Vasiliy S., and Alexander E. Mayer. "Initiation and Mechanisms of Plasticity in Bimetallic Al-Cu Composite." Metals 13, no. 1 (January 3, 2023): 102. http://dx.doi.org/10.3390/met13010102.
Abstract:
We studied the shear deformation of a laminar Al-Cu composite with (100) and (110) interfaces with a shear perpendicular to the lamellae in comparison with pure single crystal Al and Cu at strain rates of 109 s−1 and 108 s−1 and different initial pressures in the range from −3 GPa to +50 GPa. The results of molecular dynamics (MD) for the plasticity initiation are generalized by means of an artificial neural network (ANN) trained by MD data for the (100) interface, and a rate sensitivity parameter identified using MD data for different strain rates. The ANN-based approach allows us to extrapolate MD data to much lower strain rates, which are more relevant for typical dynamic loadings. The considered problem is of interest as an example of the application of the developed ANN-based approach to bimetallic systems, whereas previously it was tested only for pure metals; in addition, Al-Cu composites are of practical interest for technology. The interface between metals reduces the shear strength of the composite in comparison with both pure metals. At an initial pressure below 10 GPa, the plasticity begins in the aluminum part of the composite, while at higher pressures, the plasticity of the copper part starts first. At a pressure above 40 GPa, a phase transition in the aluminum part governs the plasticity development. All this leads to a nonmonotonic pressure dependence of the critical shear stress of the Al-Cu composite in the case of (100) and (110) interfaces without misorientation. Misorientation decreases the critical stress of the nucleation of lattice dislocation and makes the pressure dependence of this stress monotonic. Deformation modes, with a defect-free copper part and a strain-accommodating aluminum part are observed in the MD and can be useful for technological applications related to deformable conducting materials.
22
Zhou, Yuting, Xingxing Jiang, Yueshao Zheng, Sheng-Yi Xie, Yexin Feng, and Keqiu Chen. "Predicted stable high-pressure phases of copper-nitrogen compounds." Journal of Physics: Condensed Matter 34, no. 2 (October 28, 2021): 025401. http://dx.doi.org/10.1088/1361-648x/ac2f10.
Abstract:
Abstract The nitrogen-rich compounds are promising candidates for high-energy-density applications, owing to the large difference in the bonding energy between triple and single/double nitrogen bonds. The exploration of stable copper–nitrogen (Cu–N) compounds with high-energy-density has been challenging for a long time. Recently, through a combination of high temperatures and pressures, a new copper diazenide compound (P63/mmc-CuN2) has been synthesized (Binns et al 2019 J. Phys. Chem. Lett. 10 1109–1114). But the pressure-composition phase diagram of Cu–N compounds at different temperatures is still highly unclear. Here, by combining first-principles calculations with crystal structure prediction method, the Cu–N compounds with different stoichiometric ratios were searched within the pressure range of 0–150 GPa. Four Cu–N compounds are predicted to be thermodynamically stable at high pressures, Pnnm-CuN2, two CuN3 compounds with the P-1 space group (named as I-CuN3 and II-CuN3) and P21/m-CuN5 containing cyclo-N5 −. Finite temperature effects (vibrational energies) play a key role in stabilizing experimentally synthesized P63/mmc-CuN2 at ∼55 GPa, compared to our predicted Pnnm-CuN2. These new Cu–N compounds show great promise for potential applications as high-energy-density materials with the energy densities of 1.57–2.74 kJ g−1.
23
Kuczera, Pawel, and Walter Steurer. "High temperature structural study of decagonal Al-Cu-Rh quasicrystal." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C94. http://dx.doi.org/10.1107/s2053273314099057.
Abstract:
The structure of d(ecagonal)-Al-Cu-Rh has been studied as a function of temperature by in-situ single-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals (QC) [1]. The experiments were performed at 293 K, 1223 K, 1153 K, 1083 K, and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. The results obtained for the HT structure refinements of d-Al-Cu-Rh QC seem to contradict a pure phasonic-entropy-based stabilization mechanism [2] for this QC. The trends observed for the ln func(I(T1 )/I(T2 )) vs.|k⊥ |^2 plots indicate that the best on-average quasiperiodic order exists between 1083 K and 1153 K, however, what that actually means is unclear. It could indicate towards a small phasonic contribution to entropy, but such contribution is not seen in the structure refinements. A rough estimation of the hypothetic phason instability temperature shows that it would be kinetically inaccessible and thus the phase transition to a 12 Å low T structure (at ~800 K) is most likely not phason-driven. Except for the obvious increase in the amplitude of the thermal motion, no other significant structural changes, in particular no sources of additional phason-related configurational entropy, were found. All structures are refined to very similar R-values, which proves that the quality of the refinement at each temperature is the same. This suggests, that concerning the stability factors, some QCs could be similar to other HT complex intermetallic phases. The experimental results clearly show that at least the ~4 Å structure of d-Al-Cu-Rh is a HT phase therefore entropy plays an important role in its stabilisation mechanism lowering the free energy. However, the main source of this entropy is probably not related to phason flips, but rather to lattice vibrations, occupational disorder unrelated to phason flips like split positions along the periodic axis.
24
Al-Zoubi, Noura. "Elastic Parameters of Paramagnetic Fe–20Cr–20Ni-Based Alloys: A First-Principles Study." Metals 9, no. 7 (July 17, 2019): 792. http://dx.doi.org/10.3390/met9070792.
Abstract:
The single-crystal and polycrystalline elastic parameters of paramagnetic Fe0.6−xCr0.2Ni0.2Mx (M = Al, Co, Cu, Mo, Nb, Ti, V, and W; 0 ≤ x ≤ 0.08) alloys in the face-centered cubic (fcc) phase were derived by first-principles electronic structure calculations using the exact muffin-tin orbitals method. The disordered local magnetic moment approach was used to model the paramagnetic phase. The theoretical elastic parameters of the present Fe–Cr–Ni-based random alloys agree with the available experimental data. In general, we found that all alloying elements have a significant effect on the elastic properties of Fe–Cr–Ni alloy, and the most significant effect was found for Co. A correlation between the tetragonal shear elastic constant C′ and the structural energy difference ΔE between fcc and bcc lattices was demonstrated. For all alloys, small changes in the Poisson’s ratio were obtained. We investigated the brittle/ductile transitions formulated by the Pugh ratio. We demonstrate that Al, Cu, Mo, Nb, Ti, V, and W dopants enhance the ductility of the Fe–Cr–Ni system, while Co reduces it. The present theoretical data can be used as a starting point for modeling the mechanical properties of austenitic stainless steels at low temperatures.
25
Plumhoff, Alexandra M., Jakub Plášil, Edgar Dachs, Artur Benisek, Jiří Sejkora, Martin Števko, Mike S. Rumsey, and Juraj Majzlan. "Thermodynamic properties, crystal structure and phase relations of pushcharovskite [Cu(AsO<sub>3</sub>OH)(H<sub>2</sub>O) ⋅ 0.5H<sub>2</sub>O], geminite [Cu(AsO<sub>3</sub>OH)(H<sub>2</sub>O)] and liroconite [Cu<sub>2</sub>Al(AsO<sub>4</sub>)(OH)<sub>4</sub> ⋅ 4H<sub>2</sub>O]." European Journal of Mineralogy 32, no. 3 (May 11, 2020): 285–304. http://dx.doi.org/10.5194/ejm-32-285-2020.
Abstract:
Abstract. The phases pushcharovskite, geminite and liroconite were synthesized or acquired and characterized by powder X-ray diffraction, infrared spectroscopy, electron microprobe analysis, thermogravimetric analysis and optical emission spectrometry, as needed. Their thermodynamic properties were determined by a combination of acid-solution calorimetry and relaxation calorimetry, resulting in Gibbs free energies of formation (ΔfGo, all values in kilojoules per mole) of -1036.4±3.8 (pushcharovskite, Cu(AsO3OH)(H2O)⋅0.5H2O) and -926.7±3.2 (geminite, Cu(AsO3OH)(H2O)). For the natural liroconite (Cu2Al[(AsO4)0.83(PO4)0.17](OH)4⋅4H2O), ΔfGo=-2996.3±9.2 kJ mol−1. The estimated ΔfGo for the endmember Cu2Al(AsO4)(OH)4⋅4H2O is −2931.6 kJ mol−1. The crystal structure of liroconite was refined (R1=1.96 % for 962 reflections with I>3σ(I)) by single-crystal X-ray diffraction and the positions of H atoms, not known previously, were determined. Liroconite is a rare mineral, except for several localities, notably Wheal Gorland in England. Thermodynamic modelling showed that liroconite will be preferred over olivenite if the Al(III) concentration in the fluid reaches levels needed for saturation with X-ray amorphous Al(OH)3. We assume that such fluids are responsible for the liroconite formation during contemporaneous oxidation of primary Cu–As ores and pervasive kaolinization of the host peraluminous granites. pH had to be kept in mildly acidic (5–6), and the activities of dissolved silica were too low to form dioptase. The main stage with abundant liroconite formation was preceded by an acidic episode with scorodite and pharmacosiderite and followed by a late neutral to mildly basic episode with copper carbonates. Geminite and pushcharovskite, on the other hand, are minerals typical for very acidic solutions. At the studied site in Jáchymov (Czech Republic), extremely acidic water precipitates arsenolite; sulfate is removed by formation of gypsum. Geminite associates with other acidic minerals, such as slavkovite, yvonite and minerals of the lindackerite group. Pushcharovskite is metastable with respect to geminite and probably converts quickly to geminite under field conditions.
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Yoshida, Kenichi, T. Yasuda, D. Tani, and H. Nishino. "Dynamic Behavior of Two Types of Martensitic Transformations in Cu-Al-Ni Shape Memory Alloy Single Crystal by Acoustic Emission Method." Advanced Materials Research 13-14 (February 2006): 305–12. http://dx.doi.org/10.4028/www.scientific.net/amr.13-14.305.
Abstract:
Dynamic behavior of two types of martensitic transformations during tensile deformation of Cu-Al-Ni shape memory alloy single crystal has been investigated using an acoustic emission waveform analysis. Two kinds of martensitic transformations consist of β1 ⇔ β1′ (structural change of DO3 to 18R) and β1 ⇒ γ1′ (structural change of DO3 to 2H), each of which is called super-elastic and thermo-elastic martensitic transformations, respectively. These two types of martensitic transformations could be obtained during tensile deformation because of different heat treatment. The rise time at the source (the source rise time) in finite elastic solid by the modified Takashima’s method was analyzed using the acoustic emission waveform detected during the martensitic transformation. The mean source rise time to the γ1′ phase was smaller than that to the β1′ phase before yielding and became the same after yielding. The former result means that the nucleation of the γ1′ phase is faster than that of the β1′ phase because of different crystallographic structure. The latter result is that the growth rate of the γ1′ phase is the same as that of the β1′ phase.
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Vereshchagin, Oleg, Olga Frank-Kamenetskaya, and Ira Rozhdestvenskaya. "Bond valence constraints on the composition of 3d-elements bearing tourmalines." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1118. http://dx.doi.org/10.1107/s2053273314088810.
Abstract:
F.C. Hawthorne (2002) and F. Bosi (2011) showed that bond valence approach is to be applied to stability prediction of tourmaline structure with different chemical composition. Using this approach we considered bond valence constraints on occupation of Y, Z, V and W sites of Cu-, Ni-bearing tourmalines. From the standpoint of the bond valence approach, [3YW] unit is unstable if W site is fully occupied by O2-. The stability of [3YW] unit decreases along a row: 3 divalent cations → 2 divalent cations + 1 trivalent cation → 2 trivalent cation + 1 divalent cations → 3 trivalent cations if W site is fully occupied by OH- or F-. There is no limitation on 3d elements and aluminum content in [2ZYV] if V site is fully occupied by OH-. The [2ZYV] unit is unstable if V site is fully occupied by O2-. The data, obtained from calculation of bond valences are in a good agreement with results of single crystal structure refinements of synthetic Cu- (Ertl et al., 2013) and Ni-tourmalines: Cu-bearing olenite with a CuO content of 8.39 wt.% [a = 15.849(1), c =7.087(1) Å, R = 2.5%] and Ni-bearing olenite with a NiO content of 18.96 wt.% [a = 15.890(2), c = 7.1815(8), R = 3.1%]. In all cases W and V sites are predominantly occupied by OH- anions. The composition of [3YW] units are [(Cu1.80Al1.20)(OH)0.60F0.40] and [(Ni1.80Al1.20)(OH)1.00]. Breaking of charge balance with increasing of bivalent cations is maintained by increasing of portion of vacancies at X site and increasing of content of trivalent cations (Al, B) at T site.
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Xu, Xiaoyu, Jiahua Liu, Yuang Cao, Han Wang, Keqiang Zhang, Chein-Chi Chang, and Suli Zhi. "Preparation and Application of Si@Al Adsorbents for Different Pollutants Removal from Aqueous Solution." Separations 11, no. 1 (January 12, 2024): 29. http://dx.doi.org/10.3390/separations11010029.
Abstract:
This study tried to use electroflocculating precipitated waste to prepare a Si@Al adsorbent by simply mixing sodium silicate at a mass ratio of 4:1 and calcining at 200 °C for 2 h. The adsorbent was low cost, high efficiency, and could remove a variety of contaminants (organic pollutants, antibiotics, and metal ions) from water. In this study, adsorbent characterization and pollutant adsorption experiments were carried out. The results showed that: Si@Al adsorbent had uniform particles, distinct layers, a loose porous appearance, and the internal structure was scattered without a crystal structure. The optimal adsorption conditions for tetracycline were as follows: dosage of adsorbent 2.0 g/L, reaction time 10 min, pH = 4.5, and tetracycline removal rate of 97.13%. The optimal adsorption conditions for MB (MB stands for methylene blue) were an adsorption dosage of 4.0 g/L, a reaction time of 15 min, pH = 4.5–8.5, and a removal rate of 96.39%. The optimal adsorption conditions for Cu were a 2.0 g/L dosage of adsorbent, a reaction time of 30 min, a pH of 8.5, and a highest removal rate of 97.47%. It was worth noting that the effect of temperature on TC, MB and Cu was not significant. At the same time, the kinetic fitting results showed that the adsorption of MB was more consistent with the quasi-second-order kinetic model, with R2 ranging from 0.9788 to 1.0000. The adsorption of TC and Cu was more consistent with the quasi-first-order kinetic model, with R2 ranging from 0.9598 to 0.9999 and 0.9844 to 0.9988, respectively. According to the results of thermodynamics, kinetics and zero potential point, the adsorption of tetracycline and methylene blue was mainly a physical adsorption, multilayer heterogeneous or single-layer homogeneous adsorption process. The adsorption of Cu was categorized as multi-layer heterogeneous chemical adsorption. The co-existing substances had little effect on the properties of the adsorbent, and the adsorbent could be recycled 5 times. Compared with other adsorbents, the results showed that the adsorbents had obvious advantages in terms of the raw material source, preparation method, time cost and removal effect. This study provided a “waste into treasure, green and efficient” multi-pollutant adsorption method.
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Kovács, Zs, N. Q. Chinh, and J. Lendvai. "Orientation dependence of Portevin–Le Châtelier plastic instabilities in depth-sensing microindentation." Journal of Materials Research 16, no. 4 (April 2001): 1171–77. http://dx.doi.org/10.1557/jmr.2001.0161.
Abstract:
Plastic instabilities were investigated in an Al–Zn–Mg–Cu alloy by depth-sensing microhardness testing in Vickers geometry. The alloy investigated showed strong age hardening as a consequence of Guiner–Preston zone formation at room temperature. The orientation dependence of the Portevin–Le Chátelier (PLC) effect was investigated by microindentation tests in differently oriented grains. If the direction of the indentation was close to the 〈100〉 crystal axis and the diagonal of the Vickers indenter coincides with the 〈110〉 crystal direction, the PLC effect was more pronounced. Under these conditions the instabilities could be observed even after 5 h of natural aging, while the PLC effect disappeared in grains with other orientations after 2 h of aging. The orientation dependence of the indentation curves was observed up to the maximal measured imprint size (d ≈ 80 μm). It is suggested that the initialization of the PLC bands takes place in the close vicinity of indenter/sample contact surface. Considering only a uniaxial compressive stress component in the sample/indenter contact planes, in the vicinity of the indenter single sliplike and multiple sliplike conditions are attained depending on the orientation of the indenter relative to the sample. Changes of the slip conditions correlate with changes in the observation regime of instability which explains the orientation dependence.
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Mills, S. J., A. G. Christy, C. Schnyder, G. Favreau, and J. R. Price. "The crystal structure of camerolaite and structural variation in the cyanotrichite family of merotypes." Mineralogical Magazine 78, no. 7 (December 2014): 1527–52. http://dx.doi.org/10.1180/minmag.2014.078.7.02.
Abstract:
AbstractWe present Raman data for camerolaite, cyanotrichite and carbonatecyanotrichite, and using synchrotron single-crystal X-ray diffraction have solved the structure of camerolaite from the Tistoulet Mine, Padern, Aude Department, France. Camerolaite crystallizes in space group P1 with the unit-cell parameters: a = 6.3310(13) Å, b = 2.9130(6) Å, c = 10.727(2) Å, α = 93.77(3)°, β = 96.34(3)°, γ =79.03(3)º, V = 192.82(7) Å3 and Z = ⅓, with respect to the ideal formula from the refinement, Cu6Al3(OH)18(H2O)2[Sb(OH)6](SO4). The crystal structure was solved to R1 = 0.0890 for all 1875 observed reflections [Fo > 4σFo] and 0.0946 for all 2019 unique reflections. The P cell has been transformed into a C-centred cell that aids comparison with that of the structurally related khaidarkanite by aC = 2aP – bP, giving parameters a = 12.441(3), b = 2.9130(6), c = 10.727(2) Å, α = 93.77(3), β = 95.57(3), γ = 92.32(3)º and Z = ⅔ in C1. Edge-sharing octahedral ribbons Cu2Al(O,OH,H2O)8 form hydrogen-bonded layers || (001), as in khaidarkanite. The partially occupied interlayer Sb and S sites of the average structure are in octahedral and tetrahedral coordination by oxygen, respectively. They cannot be occupied simultaneously, which leads to regular alternation of [Sb(OH)6]– and SO42– groups in rods || y, resulting in local tripling of the periodicity along y for the Sb(OH)6–SO4 rods. Thus, camerolaite has a ‘host–guest’ structure in which an invariant host module (layers of Cu–Al ribbons) has embedded rod-like guest modules with a longer periodicity. Coupling between the phases of these rods is only short-range, resulting in diffuse X-ray scattering rather than sharp superstructure reflections. Similar disorder is known for parnauite, and is deduced for other members of the cyanotrichite group (cyanotrichite, carbonatecyanotrichite and khaidarkanite). Group members all share the Cu–Al ribbon module but have interlayer rods of different compositions and topologies; thus, they form a merotypic family. The low symmetry of the camerolaite average structure suggests other possibilities for structure variation in the group, which are discussed.
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Hall, E. L., A. Mogro-Campero, N. Lewis, and L. G. Turner. "Microstructural characterization of YBaCuO Films on LaAlO3 substrates." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 180–81. http://dx.doi.org/10.1017/s0424820100152872.
Abstract:
There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).
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Mills, Stuart J., Andrew G. Christy, Fernando Colombo, and Jason R. Price. "The crystal structure of cyanotrichite." Mineralogical Magazine 79, no. 2 (April 2015): 321–35. http://dx.doi.org/10.1180/minmag.2015.079.2.10.
Abstract:
AbstractWe report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].
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Schock, Hans-W. "CulnSe2 and Other Chalcopyrite-Based Solar Cells." MRS Bulletin 18, no. 10 (October 1993): 42–44. http://dx.doi.org/10.1557/s0883769400038288.
Abstract:
CuInSe2 and related chalcopyrite semiconductors are among the compound semiconductors that have been considered for thin solar cells for about the past 20 years. Recently, high efficiencies close to 17% have been achieved. This result could be the starting point for a new category of solar cells—high-performance thin-film cells—that would combine the high performance of single-crystal cells with possible low-cost thin-film processing.The development of CuInSe2 cells started in 1974, when single-crystal cells with an efficiency of 12% were reported by a group at Bell Laboratories. Soon after, thin-film solar cells were demonstrated by Kazmerski et al. CuInSe2 thin films have been deposited by evaporating the CuInSe2 source material to completion and adding Se from a separate source. It was found that straight-forward evaporation of the compound does not generally lead to films with stoichiometric composition. By coevaporation of the elements, films with any desired composition can be obtained, provided there is appropriate process control. A “bilayer” recipe developed by Boeing, namely combining Cu-rich films and In-rich films, solved the problem of combining larger grains with suitable electronic properties. By this method, the first CuInSe2 thin-film solar cells with an efficiency exceeding 10% conversion efficiency were fabricated.Alloying CuInSe2 with CuGaSe2 and CuInS2 considerably increases the potential for the innovative development of solar cells from these materials. The energy gaps covered by these alloys range from about 1 eV to about 2.4 eV The possibility of increasing the energy gap and achieving absorber layers with graded bandgaps has many advantages for the application of these materials in thin-film solar cell modules.
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Mahmud, Mohd Sabri, Zahira Yaakob, Abu Bakar Mohamad, Wan Ramli Wan Daud, and Vo Nguyen Dai Viet. "AMORPHOUS STRUCTURE IN CU-ZN-V-AL OXIDE COMPOSITE CATALYST FOR METHANOL REFORMING." IIUM Engineering Journal 19, no. 1 (June 1, 2018): 197–214. http://dx.doi.org/10.31436/iiumej.v19i1.808.
Abstract:
Cu-Zn-V-Al oxide composite catalysts were prepared using a co-precipitation method to investigate hydrogen and carbon monoxide yield of a methanol reforming reaction. The mass compositions of metals were initially determined on the Simplex Centroid statistical design. The effects of various metal compositions on the physicochemical properties of the catalyst were studied via X-ray diffractogram (XRD), temperature-programmed reduction (TPR) analyses, and reaction. XRD revealed crystals in the samples. Crystalline CuO in Cu30V30Al40 formed with the addition of zinc oxide at the metal loading below 30 wt%. A combination of zinc oxide and vanadia, however, had no Zn-V complex crystal but its scanning electron microscopy image showed the formation of string structures (AS). The catalyst that contained the AS exhibited a broad hydrogen reduction peak in the TPR analysis. Vanadium at a loading below 40 wt% with various zinc and cuprum compositions also formed small ASs and exhibited single TPR peaks. A reaction yield study revealed the optimum compositions of metal oxides when the data was fitted by response surface plots. The catalysts with high content of AS were not at the peaks however. Cu-Zn based catalysts showed the highest hydrogen yield for the reaction temperature of between 150 oC to 225 oC and vanadia-promoted catalyst with AS only appeared to be the optimum catalyst at the higher temperature. ABSTRAK: Mangkin komposit oksida Cu-Zn-V-Al disediakan menggunakan kaedah pemendakan bersama untuk mengkaji hasil hidrogen dan karbon monoksida daripada tindak balas pembentukan semula metanol. Komposisi jisim logam-logam dikenal pasti terlebih dahulu menggunakan reka bentuk statistik Simplex Centroid. Pelbagai kesan komposisi logam terhadap sifat-sifat mangkin kimia-fizikal dikaji menerusi analisis-analisis pembelauan sinar-X (XRD) dan program penurunan suhu teratur (TPR), dan tindak balas kimia. Hasil analisis XRD menzahirkan kristal pada sampel-sampel. Hablur CuO terbentuk dalam Cu30V30Al40 dengan penambahan zink oksida pada muatan logam kurang daripada 30% berat. Gabungan zink oksida dan vanadia walau bagaimanapun tidak menghasilkan hablur kompleks Zn-V, namun imbasan imej mikroskop elektron menunjukkan pembentukan struktur tetali (AS). Mangkin yang mengandungi AS menunjukkan penurunan puncak hidrogen yang lebar dalam analisis TPR. Vanadium pada muatan berat logam kurang daripada 40% berbanding komposisi zink dan kuprum juga membentuk AS kecil dan menghasilkan puncak-puncak TPR tunggal. Hasil tindak balas kajian menunjukkan komposisi optimum oksida logam apabila data ujikaji dipadankan dengan menggunakan plot permukaan respon. Mangkin yang mempunyai kandungan AS tertinggi bagaimanapun tidak berada pada puncak. Mangkin berasaskan Cu-Zn menunjukkan hasil hidrogen tertinggi bagi suhu tindak balas antara 150 oC hingga 225 oC dan mangkin yang ditambah vanadia bersama AS pula muncul sebagai mangkin optimum pada suhu lebih tinggi.
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Heenan, Alexander Reynell, Johan Hamonnet, and Aaron Timothy Marshall. "Understanding the Inconsistencies in the Literature for the CO2 Reduction Reaction on Polycrystalline Copper." ECS Meeting Abstracts MA2022-01, no. 49 (July 7, 2022): 2086. http://dx.doi.org/10.1149/ma2022-01492086mtgabs.
Abstract:
As the desire to for carbon neutral processes increases with the prominence of global warming, the electrochemical reduction of carbon dioxide has the ability to not only reduce atmospheric CO2 levels, but also produce value added chemicals such as CO, C2H4, and CHOOH using renewable energy. Polycrystalline copper is a popular electrocatalyst for the CO2 reduction reaction (CO2RR) as it is the only pure metal catalyst to reduce CO2 to products that require more than two electrons, at reasonable faradaic efficiencies [1]. This has led to the development of many novel copper-based catalysts, such as oxide derived copper, copper nanoneedles and copper nanospheres to enhance the activity and selectivity of the CO2RR [2-5]. Often when developing these unique catalysts, polycrystalline copper will be used as a reference material to show how the new material is more active and has better selectivity [2-5]. However, the literature shows substantial inconsistencies for the selectivity of the CO2RR on polycrystalline copper (under identical conditions), which brings into question the reliability of the results on the more complicated materials. For example, on polycrystalline copper, Mistry et al. reported a faradaic efficiency for methane and ethylene of 43% and 31%, respectively, at -1 V vs RHE in CO2 saturated 0.1 M KHCO3 solution [6], whereas Hori et al. reported a faradaic efficiency of 0% for both methane and ethylene under identical conditions [7]. Here, we show that the discrepancy is likely not due to a single factor alone, but it is made up of several contributing factors. These include surface pre-treatments of the polycrystalline copper [7, 8] (such as sanding, mechanical polishing, electropolishing and etching), natural variation in the crystal orientation on the copper surface [9-11], and the way that iR compensation is applied and subsequently corrected for post-experiment. It was found that the faradaic efficiency for methane and ethylene could increase by up to 140% and 124%, respectively, over a 0.035 V range, which if iR compensation is not correctly adjusted for post experiment, could lead to significant errors in the reported results. We also show that the solution resistance can change by 51% over a 6 hour period of electrolysis, requiring the solution resistance to be regularly measured throughout the experiment to be able to correctly adjust the potential post experiment. Single crystal CO2RR experiments have also shown differences between the mechanism for reducing CO on a Cu(111) surface, compared to a Cu(100) surface, which leads to different activities and selectivities [12]. Interestingly, we show electron backscatter diffraction (EBSD) measurements for different pieces of the same polycrystalline copper that have different crystal orientation distributions. References [1] S. Nitopi, E. Bertheussen, S. B. Scott, X. Liu, A. K. Engstfeld, S. Horch, B. Seger, I. E. L. Stephens, K. Chan, C. Hahn, J. K. Norskov, T. F. Jaramillo, I. Chorkendorff, Chem. Rev., 119 (2019) 7610−7672. [2] M. Ma, K. Djanashvili, W. A. Smith, Angew. Chem. Int., 55 (2016) 6680−6684. [3] L. Mandal, K. R. Yang, M. R. Motapothula, D. Ren, P. Lobaccaro, A. Patra, M. Sherburne, V. S. Batista, B. S. Yeo, J. W. Ager, J. Martin, T. Venkatesan, ACS Appl. Mater. Interfaces, 10 (2018) 8574−8584. [4] D. Raciti, K. J. Livi, C. Wang, Nano Lett., 15 (2015) 6829−6835. [5] A. Loiudice, P. Lobaccaro, E. A. Kamali, T. Thao, B. H. Huang, J. W. Ager, R. Buonsanti, Angew. Chem. Int., 55 (2016) 5789−5792. [6] H. Mistry, A. S. Varela, C. S. Bonifacio, I. Zegkinoglou, I. Sinev, Y.-W. Choi, K. Kisslinger, E. A. Stach, J. C. Yang, P. Strasser, B. R. Cuenya, Nat. Comms. 7 (2016) 12123. [7] Y. Hori, A. Murata, R. Takahashi, J. Chem. Soc., Faraday Trans. 1, 85 (1989) 2309−2326. [8] K. Jiang, Y. Huang, G. Zeng, F. M. Toma, W. A. Goddard, A. T. Bell, ACS Energy Lett., 5 (2020) 1206−1214. [9] I. Takahashi, O. Koga, N. Hoshi, Y. Hori, J. Electroanal. Chem., 533 (2002) 135−143. [10] Y. Hori, I. Takahashi, O. Koga, N. Hoshi, J. Phys. Chem. B, 106 (2002) 15−17. [11] Y. Huang, A. D. Handoko, P. Hirunsit, B. S. Yeo, ACS Catal. 7 (2017) 1749−1756. [12] K. J. P. Schouten, Z. Qin, E. Perez Gallent, M. T. M. Koper, J. Am. Chem. Soc., 134 (2012) 9864−9867.
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Acharya, Biplav, Tyler N. Pardue, Liangliang Su, Alex I. Smirnov, Donald W. Brenner, and Jacqueline Krim. "Nanotribological Performance Factors for Aqueous Suspensions of Oxide Nanoparticles and Their Relation to Macroscale Lubricity." Lubricants 7, no. 6 (June 7, 2019): 49. http://dx.doi.org/10.3390/lubricants7060049.
Abstract:
Quartz crystal microbalance (QCM) measurements of nanotribological properties of statistically diverse materials combinations of nanoparticles and substrate electrodes in aqueous suspensions are reported and compared to macroscale measurements of the same materials combinations for a subset of the nanoparticle combinations. Four ceramic nanoparticles, TiO2, SiO2, Al2O3, and maghemite (γ-Fe2O3) and ten substrate materials (Au, Al, Cr, Cu, Mo, Ni, Pt, SiO2, Al2O3, and SS304) were studied. The QCM technique was employed to measure frequency and motional resistance changes upon introduction of nanoparticles into the water surrounding its liquid-facing electrode. This series of experiments expanded prior studies that were often limited to a single nanoparticle - solid liquid combination. The variations in QCM response from one nanoparticle to another are observed to be far greater than the variation from one substrate to another, indicating that the nanoparticles play a larger role than the substrates in determining the frictional drag force levels. The results were categorized according to the direction of the frequency and motional resistance changes and candidate statistical performance factors for the datasets were generated. The performance factors were employed to identify associations between the QCM atomic scale results and the macroscale friction coefficient measurements. Macroscale measurements of friction coefficients for selected systems document that reductions (increases) in motional resistance to shear, as measured by the QCM, are linked to decreases (increases) in macroscale friction coefficients. The performance factors identified in the initial study therefore appear applicable to a broader set of statistically diverse samples. The results facilitate full statistical analyses of the data for identification of candidate materials properties or materials genomes that underlie the performance of nanoparticle systems as lubricants.
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Mordberg, L. E., C. J. Stanley, and K. Germann. "Mineralogy and geochemistry of trace elements in bauxites: the Devonian Schugorsk deposit, Russia." Mineralogical Magazine 65, no. 1 (February 2001): 81–101. http://dx.doi.org/10.1180/002646101550145.
Abstract:
AbstractProcesses of mineral alteration involving the mobilization and deposition of more than 30 chemical elements during bauxite formation and epigenesis have been studied on specimens from the Devonian Schugorsk bauxite deposit, Timan, Russia. Chemical analyses of the minerals were obtained by electron microprobe and element distribution in the minerals was studied by element mapping. Interpretation of these data also utilized high-resolution BSE and SE images.The main rock-forming minerals of the Vendian parent rock are calcite, dolomite, feldspar, aegirine, riebeckite, mica, chlorite and quartz; accessory minerals are pyrite, galena, apatite, ilmenite, monazite, xenotime, zircon, columbite, pyrochlore, chromite, bastnaesite and some others. Typically, the grainsize of the accessory minerals in both parent rock and bauxite is from 1 to 40 µm. However, even within these rather small grains, the processes of crystal growth and alteration during weathering can be determined from the zonal distribution of the elements. The most widespread processes observed are: (1) Decomposition of Ti-bearing minerals such as ilmenite, aegirine and riebeckite with the formation of ‘leucoxene’, which is the main concentrator of Nb, Cr, V and W. Crystal growth can be traced from the zonal distribution of Nb (up to 16 wt.%). Vein-like ‘leucoxene’ is also observed in association with organics. (2) Weathering of columbite and pyrochlore: the source of Nb in ‘leucoxene’ is now strongly weathered columbite, while the alteration of pyrochlore is expressed in the growth of plumbopyrochlore rims around Ca-rich cores. (3) Dissolution of sulphide minerals and apatite and the formation of crandallite group minerals: ‘crandallite’ crystals of up to 40 µm size show a very clear zonation. From the core to the rim of a crystal, the following sequence of elements is observed: Ca → Ba → Ce → Pb → Sr → Nd. Sulphur also shows a zoned but more complicated distribution, while the distribution of Fe is rather variable. A possible source of REE is bastnaesite from the parent rock. More than twelve crandallite type cells can be identified in a single ‘crandallite’ grain. (4) Alteration of stoichiometric zircon and xenotime with the formation of metamict solid solution of zircon and xenotime: altered zircon rims also bear large amounts of Sc (up to 3.5 wt.%), Fe, Ca and Al in the form of as yet unidentified inclusions of 1–2 µm. Monazite seems to be the least altered mineral of the profile.In the parent rock, an unknown mineral of the composition (wt.%): ThO2 – 54.8; FeO – 14.6; Y2O5 – 2.3; CaO – 2.0; REE – 1.8; SiO2 12.2; P2O5 – 2.8; total – 94.2 (average from ten analyses) was determined. In bauxite, another mineral was found, which has the composition (wt.%): ThO2 – 24.9; FeO – 20.5; Y2O5 – 6.7; CaO 2.0; – ZrO – 17.6; SiO2 – 8.8; P2O5 – 5.4; total – 89.3 (F was not analysed; average from nine analyses). Presumably, the second mineral is the result of weathering of the first one. Although the Th content is very high, the mineral is almost free of Pb. However, intergrowths of galena and pyrite are observed around the partially decomposed crystals of the mineral. Another generation of galena is enriched in chalcophile elements such as Cu, Cd, Bi etc., and is related to epigenetic alteration of the profile, as are secondary apatite and muscovite.
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Yu, Wei Yuan, Wen Jiang Lu, and Nai Rui Li. "Effects of Cu and Zr on the Formation and Thermal Stability of Al–Ni–Zr–Cu–Y Amorphous Alloy." Applied Mechanics and Materials 271-272 (December 2012): 36–41. http://dx.doi.org/10.4028/www.scientific.net/amm.271-272.36.
Abstract:
Al85Ni10Zr3Y2 and Al80Ni10Zr8-xCuxY2（x=1,2,3,5） alloy ribbons had been prepared by single roller melt-spinning process under vacuum conditions. The ribbons were investigated by X–ray diffraction and differential scanning calorimetry (DSC). The results revealed the strong effect of content of Cu、Zr elements on the glass forming ability and the thermal stability of the alloys. The formation of amorphous alloys are sensitive to contens of these two elements. The completely amorphous alloy or the primary amorphous phase alloy can be obtained when the content of Cu or Zr reach an optimization, otherwise only gaining crystal phase. Al80Ni10Zr7Cu1Y2 and Al80Ni10Zr3Cu5Y2 alloys possess the excellent glass forming ability, which can form the completely amorphous alloy or the composite material of the partial crystal in remaining amorphous.
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Wang, Jinxue, Khashayar Khanlari, Yali Chen, Bo Lin, Yang Zhang, and Weiwen Zhang. "Numerical/Experimental Study of Process Optimization Conducted on an Al-Cu Alloy Produced by Combined Fields of Applied Pressure and Ultrasonic Vibration." Crystals 13, no. 10 (October 7, 2023): 1466. http://dx.doi.org/10.3390/cryst13101466.
Abstract:
Single-pressure and ultrasonic action have their own unique advantages in the treatment of metal melts. When the two are combined into a composite field, the advantages of a single physical field can be fully utilized. So, the cavitation and acoustic streaming effects characteristics of an Al-5.0Cu alloy treated under different coupling process parameters, related to applied extrusion pressure and ultrasonic vibration, were analyzed by combining numerical simulation and experimental verification. The simulation results were experimentally verified by quantitative analysis of the microstructure, the melt, and its macro characteristics. The results show that the closing time t decreases with an increase in the extrusion pressure. In addition, when the ultrasonic power and extrusion force are increased simultaneously (100 MPa and 1 kW), the average grain size and the proportion of columnar grains reach the ideal effect. The influence of pressure parameters is greater, which will also lead to an increase in the proportion of columnar crystals. By optimizing the parameters, the grain size can be further reduced, the proportion of columnar crystal structure can be reduced, and fine and uniform equiaxed crystal structures can be easily obtained.
40
Srikar, V. T., and C. V. Thompson. "Diffusion and Electromigration of Cu in Single Crystal Al Interconnects." MRS Proceedings 516 (January 1998). http://dx.doi.org/10.1557/proc-516-71.
Abstract:
AbstractThe electromigration-induced transport properties of Cu in Al-Cu alloys, and their effect on electromigration lifetimes in interconnects with bamboo grain structures are not well understood. To isolate and study the mechanisms and kinetics of Cu diffusion and electromigration in interconnects for which grain boundary transport is not dominant, we have developed a test structure consisting of parallel Al single crystal lines, with every alternate line terminating in contact pads. Cu is locally added to the same regions in all the lines, and the effect of temperature and electric field can be simultaneously characterized by analyzing the Cu concentration profile measured using electron-probe microanalysis. Comparison of the calculated values of diffusivities with the diffusivity of Cu through the Al lattice, and through dislocation cores in Al, suggests that the path of diffusion of Cu in Al single crystals is along the Al/AlOx interface.
41
Yawny, A. A., M. Sade, and F. C. Lovey. "Actuator Applications with Single-Crystals of Cu-Zn-Al Shape Memory Alloy." MRS Proceedings 459 (1996). http://dx.doi.org/10.1557/proc-459-369.
Abstract:
ABSTRACTIn the present work the use of single-crystals of Cu-Zn-Al Shape Memory Alloys (SMA) in actuator applications is analyzed. The actuator considered here, a device capable of doing work in response to temperature changes, is based on a single-crystal nucleus of a Cu-Zn-Al SMA coupled to a conventional spring that represents the load to be displaced. A special experimental stage was designed for performing controlled thermal cycles under load. In this way the effects of different parameters (cycle number, friction, temperature range, load level) on the actuator behavior can be studied. From the results obtained, the use of a single-crystal of an SMA in a thermostatic device is analyzed and compared with the commercial wax actuator performance.
42
Romero, Francisco Javier, José-María Martín-Olalla, María Carmen Gallardo, Daniel Soto-Parra, Ekhard K. H. Salje, Eduard Vives, and Antoni Planes. "Scale-invariant avalanche dynamics in the temperature-driven martensitic transition of a Cu-Al-Be single crystal." Physical Review B 99, no. 22 (June 20, 2019). http://dx.doi.org/10.1103/physrevb.99.224101.
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Yakubovich, Olga V., Galina V. Kiriukhina, Sergey V. Simonov, Anatoly S. Volkov, and Olga V. Dimitrova. "(Na,Li)3(Cl,OH)[Cu3OAl(PO4)3]: a first salt-inclusion aluminophosphate oxocuprate with a new type of crystal structure." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 79, no. 1 (January 12, 2023). http://dx.doi.org/10.1107/s2052520622011696.
Abstract:
The synthesis and characterization of a first salt-inclusion aluminophosphate oxocuprate, (Na,Li)3(Cl,OH)[Cu3OAl(PO4)3], obtained as single crystals, is reported. A novel phase, with a strongly pseudo-orthorhombic structure, is described as a monoclinic crystal structure established by the study of a pseudomerohedric microtwin. It was investigated using scanning electron microscopy, microprobe analysis and low-temperature X-ray diffraction. The composite crystal structure represents an original framework assembled from Cu-centered polyhedra, AlO6 octahedra and PO4 tetrahedra with channels, which incorporate the Na/Li salt component [(Na,Li)3(Cl,OH)]2+ that ensures electroneutrality of the compound. Layers of strongly corrugated chains of Cu-centered octahedra with shared edges and linked by PO4 tetrahedra are shown to be topologically identical with the layers also built from Cu-centered polyhedra and AsO4/VO4 tetrahedra forming the crystal structure of a fumarolic mineral aleutite, (M 0.5Cl)[Cu5O2(AsO4)(VO4)] [Siidra et al. (2019). MinMag, 83, 847–853]. `Sawtooth chains' and pairs of Cu-centered octahedra inherent in the title structure may be of interest in solid-state physics, engaging studies in the field of low-dimensional and frustrated magnetism.
44
Lograsso, T. A., and A. R. Ross. "Processing Of Al-Cu-Fe Quasicrystalline Single Grains." MRS Proceedings 553 (1998). http://dx.doi.org/10.1557/proc-553-3.
Abstract:
AbstractThe phase equilibria of the Al-Cu-Fe quasicrystalline phase (y phase) is complex and conventional crystal growth techniques like the Bridgman and Czochralski methods are not applicable in preparation of large crystals. Large single grains of the y phase been have prepared by either slow cooling or isothermal anneals. In the later technique, arc melted ingots were subjected to either single or multiple heat treatments between 825 and 840°C to encourage grain growth. Following heat treatment, grains of the icosahedral phase are found either as isolated pentagonal-faceted crystals within the ingot or within clusters of intergrown grains. The growth of the large grains is independent of the sample processing history of the sample, is facilitated by the presence of liquid at the growth temperatures and is constrained by the physical dimension of the ingot. The microstructure of both grain types is similar containing a minor quantity (on the order of 5–10 %) of a second phase and a high degree of porosity in the as-grown state. The second phase is usually present as a thin layer between adjacent grains or associated with a pore within a single grain. The grain porosity is distributed throughout the ingot. These defects can be removed through post-growth hot isostatic pressing and anneal treatments.
45
Moyer, L. E., G. S. Cargill, W. Yang, B. C. Larson, and G. E. Ice. "X-ray Microbeam Diffraction Measurements in Polycrystalline Aluminum and Copper Thin Films." MRS Proceedings 795 (2003). http://dx.doi.org/10.1557/proc-795-u1.7.
Abstract:
ABSTRACTThermally induced residual strains in polycrystalline Cu and Al films on single crystal Si and glass substrates, respectively, have been examined on a grain-by-grain basis by x-ray microbeam diffraction. The crystallographic orientation and the deviatoric strain tensor, εij*, are determined for each grain by white beam Laue diffraction. From grain orientation mapping and strain tensor measurements, information is obtained about the distributions of strains for similarly oriented grains, about strain variations within single grains, and about grain-to-grain correlations of strains. This type of information may be useful in developing and testing theories for intergrain effects in strain evolution in polycrystals.
46
Yoshikazu, Nakanishi, Junko Ide, Jun Kondo, Shinji Fukao, Katsumi Handa, Tatsunori Tochio, Yoshiaki Ito, Akikazu Tanaka, and Shinzo Yoshikado. "Ozone Gas Generator Using Uniaxially Polarized LiTaO3 Single Crystal." MRS Proceedings 1034 (2007). http://dx.doi.org/10.1557/proc-1034-k10-62.
Abstract:
AbstractThe phenomenon that a ferroelectrics crystal carries out intrinsic polarization by the temperature change generally is known. The Ozone gas generation was investigated due to a strong electric field of this crystal under atmospheric pressure . When we added a rapid temperature change to the crystal, the charge non–equilibrium occurs around the crystal. Oxygen is influenced due to the non-equilibrium in charge and ozone is considered to be generated. Therefore, we used the high electric field induced due to the polarization of a ferroelectrics crystal in order to produce the ozone under atmospheric pressure.As a result, we were able to produce ozone of the density of 400ppb in a oxygen gas flow of 1.5 liters per minute using this simple system: The crystals (Yamaju Co. Ltd. and Sumitomo metal mining Co. Ltd.) are used in thickness of 3, 5, 7, 10, 20, and 30 mm with a diameter of 4 inches, respectively. They are poled crystals.Experiments on the maximum temperature (300 degree), the temperature gradient (100 degree/10 minite), and substrate materials(Cu and Al), the thickness of the crystal, and z face etc. were carried out during the temperature of LiTaO3 single crystal from 20C to about 300C. It is found that the amount of the ozone production increases rapidly, when the maximum temperature of LiTaO3 single crystal is raised and have a relation with the thickness of the crystal. However, the amount of the ozone production doesn't closely related with the X-ray generation that we use the crystal for.In the present study, when the thickness of the crystal became large, polarization voltage became high, but generated efficiency of ozone was not necessarily proportional to thickness.
47
Thomas, R. E., J. H. Perepezko, and J. D. Wiley. "Interfacial Reactions Between Amorphous W-Si Thin Films And Polycrystalline Overlayers." MRS Proceedings 54 (1985). http://dx.doi.org/10.1557/proc-54-127.
Abstract:
ABSTRACTInteractions between amorphous metal thin films and either a substrate or an overlayer can limit their effectiveness as diffusion barriers. We have found in previous studies that Au and Al polycrystalline thin films in contact with amorphous W-Si lowers the crystallization temperature of the a-(W-Si) by at least 100C. In contrast Cu and Mo have no apparent effect on the stability of the amorphous layer. The mechanisms leading to premature crystallization are not well understood. Amorphous W .72Si.28 was deposited by D.C. sputtering onto single crystal Si substrates. Overlayers of Al were then evaporated onto the W-Si. Using Auger electron spectroscopy depth profiling coupled with cross-section TEM, we have studied interfacial reactions between the amorphous layer and polycrystalline Al. Auger profiling results show that in the case of Al overlayers, W and Si diffuse out of the a-(W-Si) into the Al where WAl12 forms. These results can be explained in the context of three binary diffusion couples, W-Si, W-Al, Al-Si, and the individual interactions associated with these couples.
48
Yamada, Isao. "Effects of Ionized Cluster Beam Bombardment on Epitaxial Metal Film Deposition on Silicon Substrates." MRS Proceedings 128 (1988). http://dx.doi.org/10.1557/proc-128-113.
Abstract:
ABSTRACTThe effects of ion beam bombardment during ionized cluster beam (ICB) deposition of metal films on Si(111) and Si(100) substrates have been discussed. In the case of Al deposition, films have been epitaxially deposited on Si(lll) and Si(100) substrates at near room temperature. On Si(111) substrates, nearly perfect Al single crystal films could be formed. On Si(100) substrates, Al bicrystals have been grown epitaxially. A remarkable fact concerning these results is that the epitaxial films could be formed at nearly room temperature and on a large lattice mismatch (25%) substrate surface. Atomic resolution TEM analysis suggests that the epitaxy of Al occurs not only on Si surfaces but also at Al/Al grain boundaries. These epitaxial films exhibit extremely high thermal stability and long electromigration life time. To understand the deposition features and film characteristics, the effects of ICB bombardment on the film growth at the initial stage of the deposition and the resultant film structure have been studied. The results show that the role of very low energy ion bombardment is especially important in forming epitaxial metal films. Depositions of Au and Cu on Si substrates have also been made to understand whether ICB deposition may improve the characteristics of other metal films. Preliminary results of these film depositions are also obtained.
49
Chakoumakos, B. C., Edward Sonder, and B. C. Sales. "Physical Properties of Bi2sr2cuo6, the Semiconducting Phase, Structurally Distinct from the N=L Bi‐Cuprate Superconductor." MRS Proceedings 169 (1989). http://dx.doi.org/10.1557/proc-169-103.
Abstract:
AbstractThe stable phase that forms near 2:2:1 in the Bi‐Sr‐Cu oxide system is now recognized as a semiconducting phase structurally distinct from the n = 1 Bi‐cuprate superconductor, whose actual composition (Bi2Sr2‐xCuO6‐y, x= 0.1‐0.25, y=0‐0.5) is deficient in Sr. The 2:2:1 phase forms by a slow solid‐state replacement of the superconducting phase for compositions near 2:2:1. It also can be grown from melt compositions involving several phase assemblages, but single‐phase products are not obtained, implying incongruent melting. Alumina and zirconia crucibles promote the growth of the superconducting phase by reacting with the melt to remove Sr, whereas Au crucibles promote the growth of the 2:2:1 phase. Owing to its fine‐grained, fibrous habit, structural characterization has been difficult. Of the unit cells proposed, the C‐centered monoclinic cell of Roth et al. provides the best fit to our x‐ray powder and single‐crystal precession data, a = 24.522(9), b = 5.426(2), c = 21.983(9) Å, β = 105.00(3)°. Perfect prismatic cleavages intersecting at ‐148° and ‐32° are indexed as {100} and {‐201} forms. Although, the superconducting n = 1 Bi‐cuprate exhibits variable Sr and O contents, the 2:2:1 phase appears to be a single composition with no oxygen exchange observed by TGA, although it may be somewhat deficient in Cu. The 2:2:1 phase is semiconducting as determined by electrical resistivity measurements, with an apparent activation energy of 0.013 eV. For a 2:2:1 stoichiometry, the measured density of ‐7.2. g/cm3 implies 16 formula units per cell.
50
Sharma, A., D. Datta, and R. Balasubramaniam. "Prediction of tool wear constants for diamond turn machining of CuBe." Journal of Micromanufacturing, July 30, 2020, 251659842093099. http://dx.doi.org/10.1177/2516598420930992.
Abstract:
While several studies in diamond turning of homogeneous materials like Cu, Al, and Si are well published, there is a lack of understanding about tool wear in case of heterogeneous materials like CuBe. Severity of the tool wear can be understood from the magnitude of the wear coefficients, and the magnitude of these coefficients is influenced by the wear mechanism. Hence, this study is aimed to calculate the wear coefficients from a known tool wear model in diamond turn machining of CuBe. Molecular dynamics simulation (MDS) results show that stress and temperature are responsible for increasing rate of tool wear. From the experimental results, change in the tool cutting edge radius due to wear was obtained and the temperature and stress for various a/r were found out using MDS. With these data, the wear coefficients, A & B, from a wear model for diamond turning were calculated. This methodology of using MDS to obtain stress and temperature for various a/ r wherein, values of r are obtained from a single machining trial on actual material, will be useful for calculating the wear coefficients for the combination of single crystal diamond tool with various work piece materials and their activation energies.