Gotowe bibliografie tematyczne / Disorder - Single Crystalline Oxides

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Gotowa bibliografia na temat „Disorder - Single Crystalline Oxides”

Autor: Grafiati

Data publikacji: 7 września 2023

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Artykuły w czasopismach na temat "Disorder - Single Crystalline Oxides"

Spinolo, G., i U. Anselmi Tamburini. "Stacking Faults in Ca(OH)2 Produced by Vapour Phase Hydration". Zeitschrift für Naturforschung A 40, nr 1 (1.01.1985): 73–78. http://dx.doi.org/10.1515/zna-1985-0113.

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The diffraction profiles of a thin single crystal with stacking faults were calculated with the theory of diffraction of a one-dimensionally disordered crystal (Kakinoki, Komura, Allegra) by including the effect of crystallite thickness. The results hold for generalized close packed structures.An application to calcium hydroxide is discussed: the stacking faults significantly contribute to the disorder of poorly crystalline forms of Ca(OH)2 produced by reaction of calcium oxide with water vapour at room temperature.

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Rupp, Jennifer L. M., Barbara Scherrer, Julia Martynczuk i Ludwig J. Gauckler. "Self-Limited to Parabolic Grain Growth Kinetics in Metal Oxide Thin Films". Materials Science Forum 715-716 (kwiecień 2012): 333. http://dx.doi.org/10.4028/www.scientific.net/msf.715-716.333.

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Distinctive microstructure engineering of amorphous to nanocrystalline electroceramic thin films is of high relevance for integration in low to high temperature operating MEMS-devices. Up to now, kinetic rules of nucleation, crystallization and grain growth of precipitation-based ceramic thin films are unknown. In this study, general rules for the crystallization and grain growth kinetics of a pure single-phase metal oxide thin film with only one kind of cation, i.e. ceria, made by spray pyrolysis from a precursor with one single organic solvent is discussed [1,. The near-and long range disorder is studied via Raman, DSC investigation of crystallization enthalpy, XRD, SEM and TEM for amorphous to fully crystalline state. These 400 nm thick-thin films were dense, crack-free and amorphous directly after deposition on a sapphire substrate. Briefly, above deposition temperature crystallization sets in with respect to temperature and persists over a broad temperature range from 400 to 950°C. In this regime, biphasic amorphous-crystallien films exist and grain growth proceeds simultaneously to crystallization. Isothermal grain growth studies showed that after short dwell times of 10-20h stable microstructures established following self-limited grain growth law [. In this state, driving force for the crystallization is the reduction of free enthalpy for phase transformation and interface diffusion prevails. A transition to classical grain curvature-driven parabolic grain growth kinetics appeared once the material reached the fully crystalline state for average grain sizes larger than 140 nm and higher annealing temperatures. Volume diffusion was then activated in addition to the interface diffusion. It was found that once crystallized the material shows independent on processing route equal XRD density and microstrain, as well as Raman characteristics. However, dependent on processing conditions i.e. choice of organic and, according, deposition temperature of the film amorphous states vary and affect strongly crystallization and grain growth history for the biphasic films.

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Khanvilkar, M. B., A. K. Nikumbh, S. M. Patange, R. A. Pawar, N. J. Karale, D. V. Nighot, P. A. Nagwade, M. D. Sangale i G. S. Gugale. "Structural, electrical and magnetic properties of substituted pyrochlore oxide nanoparticles synthesized by the co-precipitation method". Physics and Chemistry of Solid State 22, nr 2 (16.06.2021): 353–71. http://dx.doi.org/10.15330/pcss.22.2.353-371.

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Five substituted pyrochlore nanooxides such as Nd1.9Ho0.1Zr1.8Ce0.2O7, La1.95Ce0.05Zr0.29Ce1.71O7, Y1.79Pr0.21Ru1.99Pr0.01O7, Dy1.9Yb0.1Mn1.93Cu0.07O7 and Dy1.99Sr0.01Sn2O7 were synthesized by coprecipitation method. These precursors were monitored by thermal studies (TGA-DTA). The prepared nanosized substituted pyrochlore oxides were characterized by EDS, XRD, SEM, TEM, d. c. electrical conductivity, Thermoelectric power, Hall effect measurement, dielectric properties and magnetization measurements. XRD confirmed the formation of a single phase crystalline substituted pyrochlores with a cubic nature of nanoparticles. All substituted compounds were adopted a stable pyrochlore structure with rA3+/rB4+ = 1.395 except La1.95Ce0.05Zr0.29Ce1.71O7 compound, which has rA3+/rB4+ = 1.175 indicate disorder pyrochlore structure (i.e. fluorite structure). The temperature dependence of d. c. electrical conductivity for all substituted pyrochlores exhibits two distinct slopes with a break. This discontinuity can be attributed to extrinsic to intrinsic semiconducting properties. The thermoelectric power and Hall effect measurements for all compounds were confirmed the p-type semiconductivity except Y1.79Pr0.21Ru1.99Pr0.01O7 compound and which showed n-type semiconductivity. The dielectric constant (ε’) and dielectric loss (tan δ) i. e dissipation factor decreases with an increase in frequencies and reaching constant at particular frequencies. The applied field dependence of magnetization curve at room temperature (300 K) for Nd1.9Ho0.1Zr1.8Ce0.2O7, Y1.79Pr0.21Ru1.99Pr0.01O7 and Dy1.9Yb0.1Mn1.93Cu0.07O7, showed hysteresis loop with a small kink around the origin and which can be attributed to small but definite ferromagnetic ordering along with significant paramagnetic and superparamagnetic components. The magnetization at 2K showed a clear hysteresis loop for Dy1.9Yb0.1Mn1.93Cu0.07O7 and Dy1.99Sr0.01Sn2O7 pyrochlores are soft (weak) ferromagnets.

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Welberry, Richard, i Darren Goossens. "Local order in wüstite. Fe1-xO, using a PDF approach". Acta Crystallographica Section A Foundations and Advances 70, a1 (5.08.2014): C873. http://dx.doi.org/10.1107/s2053273314091268.

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Many minerals (and materials more widely) show evidence of strong and complex local structural ordering. This local ordering can affect a material's mechanical properties, its transport properties (for example, how vacancies relate to oxygen transport through the structure) and its thermodynamics, and so is clearly of prime importance. For crystalline materials the analysis of single crystal diffuse scattering (SCDS) is the most definitive way of determining local structure but for many minerals (and materials more widely) single crystals of a sufficient size for such studies are often not readily obtainable and powder diffraction data must suffice. While conventional powder XRD (e.g. using Rietveld refinement) can provide information about the average crystal structure, total scattering (TS) – which includes both Bragg peaks and diffuse scattering – is needed if information about the local structure and short-range order is to be gained. The pair distribution function (PDF) analysis of such total scattering data has become a widely used technique for extracting such local structural information from a wide variety of materials including crystalline powders, nano-materials, amorphous materials, glasses and liquids. The aim of the present work is to explore the sensitivity of the PDF methodology to various aspects of disorder and short-range order for a mineral system for which the local structure has been characterised previously using SCDS. The system chosen for this study is the non-stoichiometric iron oxide wüstite, (Fe1–xO, x = 0.057). The X-ray diffraction patterns obtained from a single crystal of wüstite show strong and richly structured diffuse scattering (see Fig. 1). This has enabled a detailed model of the defect structure to be established. The aim is to assess to what extent this defect structure model could have been established using PDF analysis of powder diffraction data.

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Ling, Chris. "Modulated order in ionic conductors: a fine line between helping and hindering". Acta Crystallographica Section A Foundations and Advances 70, a1 (5.08.2014): C228. http://dx.doi.org/10.1107/s205327331409771x.

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"Solid-state ionic conduction relies on essentially conflicting structural properties: long-range crystalline order, to provide structural stability (as fuel cell membranes, battery cathodes etc.); and short-range disorder, to provide smooth conduction pathways without deep local energy minima that could trap the conducting species. Materials that combine these features are generally metastable, and prone to ordering into complex modulated structured that can only be described in (3+n) dimensions using the superspace formalism. Such ordering would normally be expected to seriously compromise conduction properties. However, low-temperature modulated structures can be effective and stable precursors to high-temperature ionic conductors - and, in some cases, can coexist with regions of local disorder that actually enhance conduction. The relationship between modulated order and ionic conduction is relatively little studied, but some of our recent work points to its potential importance. This presentation will focus on two examples: the (3+3)-dimensional commensurately modulated proton conductor Ba4Nb2O9.1/3H2O; [1,2] and the (3+3)-dimensional incommensurately modulated oxide ion conductor ""Type II"" Bi2O3.xNb2O5 (for which a single-crystal neutron diffraction pattern and the refined structure are shown below). [3] The aim is to show how modulated structures can be designed and manipulated to optimise technological performance by striking a balance between stabilising the overall framework while destabilising the conduction pathways."

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Sarkar, Toton, Sani Kundu, Gurupada Ghorai, Pratap Kumar Sahoo i Ashis Bhattacharjee. "Structural, spectroscopic and morphology studies on green synthesized ZnO nanoparticles". Advances in Natural Sciences: Nanoscience and Nanotechnology 14, nr 3 (16.06.2023): 035001. http://dx.doi.org/10.1088/2043-6262/acd8b6.

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Abstract Zinc oxide nanoparticles (ZnO NPs) were synthesised using Tabernaemontana divaricata flower extract (TFE) in different weight percentages by facile, eco-friendly and cost-effective green synthesis method. Formation and structure of the ZnO NPs were studied by powder XRD, FT−IR, Raman and TEM studies. The crystals formed are of hexagonal wurtzite structure with biological functional groups attached. Average crystallite size of the ZnO NPs (17.5−23.3 nm) was obtained from the analysis of powder XRD data which increased with increase of TFE amount while the estimated values of dislocation density and micro-strain exhibited an opposite behaviour. The optical (direct and indirect) energy band gap values estimated using UV–vis DRS spectral data decreased with increasing amount of TFE. The photoluminescence spectra for the ZnO NPs exhibited multiple peaks spread over the visible region with one peak in the NIR region indicating the existence of various defect levels of Zn and O. Position of these defect levels within the band gap was assigned which is significantly modulated by TFE. TFE amount-dependent peak shift and/or peak broadening were observed in the Raman spectra of the ZnO NPs which were correlated with the growing disorder in the crystals induced by the extract molecules. FESEM study showed the agglomerated NPs with quasi-spherical morphology. Particle size of the ZnO NPs was estimated from FESEM images. EDX study indicated that increased presence of TFE in ZnO decreased the oxygen content in the synthesised material. HRTEM study revealed the agglomeration of nanoparticles with single crystalline nature. Present study convincingly established that flower extract used for the green synthesis efficiently modified the structure and optical property, defect levels and morphology of the potentially useful ZnO nanoparticles.

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Chen, Yancheng, Yingjie Lu, Xun Yang, Shunfang Li, Kaiyong Li, Xuexia Chen, Zhiyang Xu, Jinhao Zang i Chongxin Shan. "Bandgap engineering of Gallium oxides by crystalline disorder". Materials Today Physics 18 (maj 2021): 100369. http://dx.doi.org/10.1016/j.mtphys.2021.100369.

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Kim, Shin-Ik, Hyung-Jin Choi, Gwangyeob Lee, Chang Jae Roh, Inki Jung, Soo Young Jung, Ruiguang Ning i in. "3D architectures of single-crystalline complex oxides". Materials Horizons 7, nr 6 (2020): 1552–57. http://dx.doi.org/10.1039/d0mh00292e.

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We proposed 3D architectures of complex oxides as a way to derive novel properties: various 3D shapes were formed by self-shaped free-standing membranes, and curvature-induced polarization in an otherwise nonpolar material was observed.

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Szlawska, M., i D. Kaczorowski. "Disorder-driven low-temperature anomalies in single-crystalline Ce2Co0.4Rh0.4Si3.2". Journal of Physics: Condensed Matter 25, nr 25 (6.06.2013): 255601. http://dx.doi.org/10.1088/0953-8984/25/25/255601.

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Yeom, Eun Joo, Seong Sik Shin, Woon Seok Yang, Seon Joo Lee, Wenping Yin, Dasom Kim, Jun Hong Noh, Tae Kyu Ahn i Sang Il Seok. "Controllable synthesis of single crystalline Sn-based oxides and their application in perovskite solar cells". Journal of Materials Chemistry A 5, nr 1 (2017): 79–86. http://dx.doi.org/10.1039/c6ta08565b.

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Rozprawy doktorskie na temat "Disorder - Single Crystalline Oxides"

Nowotny, Maria Materials Science &amp Engineering Faculty of Science UNSW. "Defect disorder, semiconducting properties and chemical diffusion of titanium dioxide single crystal". Awarded by:University of New South Wales. School of Materials Science and Engineering, 2006. http://handle.unsw.edu.au/1959.4/27223.

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Semiconducting properties and related defect disorder for well defined TiO2 single crystal were studies. Semiconducting properties have been determined using simultaneous measurements of two independent electrical properties, including electrical conductivity, ??, and thermoelectric power, S, at elevated temperatures (1073-1323 K) in the gas phase of controlled oxygen activity (10-10 Pa < p(O2) < 75 kPa). Measurements of s and S were conducted (i) in the gas/solid equilibrium and (ii) during equilibration. Oxygen vacancies have been identified as the predominant defects in TiO2 over a wide range of p(O2). Individual conductivity components related to electrons, electron holes and ions, were determined from the obtained ?? data. The effect of p(O2) on these individual components was considered in the form of a diagram. This work led to the discovery of the formation and diffusion of Ti vacancies. However, the obtained diffusion data indicate that, in the temperature ranges commonly used in studies of semiconducting properties (1000-1400K), the Ti vacancies concentration is quenched and may thus be assumed constant. In addition it was shown that Ti vacancies in appreciable concentrations form only during prolonged oxidation. It was determined that the discrepancies in the reported n-p transition point are related to the concentration and spectrum of impurities as well as the concentration of Ti vacancies. It has been shown that the n-p transition point in high-purity TiO2 is determined by the Ti vacancy concentration. A well defined chemical diffusion coefficient, Dchem, was determined using kinetic data obtained during equilibration. A complex relationship between p(O2) and Dchem was observed. These data showed a good agreement between the obtained diffusion data and defect disorder. Examination of the determined equilibration kinetics, led to the discovery of two kinetic regimes, the result of the transport of defects at different mobilities. The determined data are considered well defined due to the following reasons: 1. The studied specimen was of exceptionally high purity and free of grain boundaries (single crystal) 2. The specimen was studied in the gas phase of controlled and well defined oxygen activity which was continuously monitored. 3. Whenever the experimental data were measured in equilibrium, the gas/solid equilibrium has been verified experimentally. 4. A good agreement between the two, self-confirmatory, electrical properties, including ?? and S has been determined simultaneously and independently. The defect disorder model derived in the present work may be used for tailoring controlled semiconducting properties through the selection of annealing conditions involving the temperature and oxygen activity.

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Raithel, Dominic [Verfasser], i Richard [Akademischer Betreuer] Hildner. "Disorder Phenomena in Conjugated Oligomers and Polymers : From Single Chains to Crystalline Aggregates / Dominic Raithel ; Betreuer: Richard Hildner". Bayreuth : Universität Bayreuth, 2018. http://d-nb.info/1156920671/34.

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Kokkaliaris, Stylianos. "Investigation of the vortex phase diagram and dynamics in single crystalline samples of the high temperature superconductor YBaâ†2Cuâ†3Oâ†7â†-â†#delta#". Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310294.

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Fleurette-Delobbe, Valérie. "Variations du type structural reo::(3) dans des fluorures et oxyfluorures de niobium iv : etude des interactions magnetiques". Paris 6, 1987. http://www.theses.fr/1987PA066373.

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Determination de la structure cristalline de nbf::(4) par diffraction de rayons x et de neutrons: structure bidimensionnelle a octaedres nbf::(6) etires; mise en evidence d'interactions antiferromagnetiques d'apres la variation thermique de la susceptibilite magnetique. Nbof::(2) possede le type structural reo::(3); absence de l'antiferromagnetisme attendu. Etude des proprietes magnetiques de tif::(3) et tinbof::(5): existence de couplages antiferromagnetiques avec des temperatures de neel de 48 et 54k respectivement. Determination des structures nucleaire et magnetique de fenbf::(6) qui est antiferromagnetique avec une composante ferromagnetique tres faible; etude par effet moessbauer: il y aurait une inversion cationique partielle et on determine les temperatures de mise en ordre pour les sites correspondants

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Fanchon, Eric. "Etude structurale de conducteurs ioniques unidimensionnels de type hollandite". Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37604938h.

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Renaud, Gilles. "Ordre chimique et désordre topologique dans les solutions solides AuNi : étude par résistivité et par absorption et diffusion du rayonnement synchrotron X". Grenoble 1, 1988. http://www.theses.fr/1988GRE10134.

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Caracterisation precise de la tendance a l'ordre a courte distance dans le monocristal au::(80) ni::(20): l'alliage est aleatoire en premier voisin, mais il existe une faible tendance a l'homocoordination en second voisin. Determination dans tout le domaine de composition des valeurs des trois distances moyennes partielles ainsi que de la largeur et de l'asymetrie de leur distribution. Mesure de l'effet de coeur dans les alliages dilues. Simulation par ordinateur des distorsions du reseau. Evaluation selon un modele harmonoque de l'energie elastique

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Hung, Wei-Jie, i 洪偉傑. "Fabrication of Transparent Conductive Oxides for Single-Crystalline n-type Silicon Hetero-Junction Solar Cells". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/50732695248536570600.

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碩士
華梵大學
機電工程學系博碩專班
98
This paper is aimed to improve the efficiencies of silicon solar cell using semiconductor fabrication technologies. The research first adopts n-type (100) silicon wafers as substrates, and applies KOH etching in the photolithography process to form inverted pyramid structures. The density of the inverse pyramid structures is varied to investigate its impact factor on the reflectivity for the solar cells. In addition, the paper performs high-density plasma chemical vapor deposition to fabricate amorphous silicon thin films. Then, the author can study solar cells performances with single crystal / hydrogenised amorphous silicon heterojunctions, the effects of p-type amorphous silicon films deposited over p-type single crystal films, as well as the influences from p-type amorphous silicon layers and intrinsic layers. Also, the research executes ion implantation to fabricate BSF layers, which are intended to decrease the carrier recombination rate within the interfacing regions, and to improve the minority carrier collection rates. Furthermore, this research employes RF sputtering system to fabricate AZO transparent conductive thin films, and then learns the effects of adjusted processing parameters to the electrical and optical film properties. In the end, hydrogen plasma is used to perform the film post-processing, and the conductive films are then utilized as solar cell electrodes. After using a semiconductor parameter analyzer to perform a series of experimental measurements, the obtained IV curves suggest that the prototyped solar cells can obtain an open circuit voltage Voc = 0.60V, a short circuit current Jsc = 30mA/cm2, a fill factor FF of 62.08%, and an actual efficiency is about 11.13%.

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Części książek na temat "Disorder - Single Crystalline Oxides"

van den Berg, J., P. H. Kes, P. Koorevaar, G. J. Nieuwenhuys, J. A. Mydosh, M. J. V. Menken i A. A. Menovsky. "Flux Pinning and Thermally Activated Flux Flow Behavior in Single Crystalline YBa2Cu3O7 and Bi2Sr2CaCu2O8". W Oxygen Disorder Effects in High-T c Superconductors, 127–39. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0561-3_10.

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Bogomol, Iurii, i Petro Loboda. "Directionally Solidified Ceramic Eutectics for High-Temperature Applications". W MAX Phases and Ultra-High Temperature Ceramics for Extreme Environments, 303–22. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-4066-5.ch010.

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The processing techniques, microstructures, and mechanical properties of directionally solidified eutectic ceramics are reviewed. It is considered the main methods for preparing of eutectic ceramics and the relationships between thermal gradient, growth rate, and microstructure parameters. Some principles of coupled eutectic growth, main types of eutectic microstructure and the relationship between the eutectic microstructure and the mechanical properties of directionally solidified eutectics at ambient and high temperatures are briefly described. The mechanical behavior and main toughening mechanisms of these materials in a wide temperature range are discussed. It is shown that the strength at high temperatures mainly depends on the plasticity of the phase components. By analyzing the dislocation structure, the occurrence of strain hardening in single crystalline phases during high-temperature deformation is revealed. The creep resistance of eutectic composites is superior to that of the sintered samples due to the absence of glassy phases at the interfaces, and the strain has to be accommodated by plastic deformation within the domains rather than by interfacial sliding. The microstructural and chemical stability of the directionally solidified eutectic ceramics at high temperatures are discussed. The aligned eutectic microstructures show limited phase coarsening up to the eutectic point and excellent chemical resistance. Directionally solidified eutectics, especially oxides, revealed an excellent oxidation resistance at elevated temperatures. It is shown sufficient potential of these materials for high-temperature applications.

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Streszczenia konferencji na temat "Disorder - Single Crystalline Oxides"

Samuel, B. A., C. M. Lentz i M. A. Haque. "Experimental Study of Structure-Electrical Transport Correlation in Single Disordered Carbon Nanowires". W ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11739.

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We present experimental results characterizing the changes in electrical transport of single disordered carbon nanowires (diameter 150–250 nm) to the changes in microstructure within the nanowires induced by synthesis temperature. The material system studied is a nanoporous, semiconducting disordered carbon nanowire obtained from the pyrolysis of a polymeric precursor (polyfurfuryl alcohol). Unlike the other allotropes of carbon such as diamond, graphite (graphenes) and fullerenes (CNT, buckyballs), disordered carbons lack crystalline order and hence can exhibit a range of electronic properties, dependent on the degree of disorder and the local microstructure. Such disordered carbon nanowires are therefore materials whose electronic properties can be engineered to specifications if we understand the structure-property correlations. Using dark DC conductivity tests, measurements were performed from 300K to 450K. The charge transport behavior in the nanowires is found to follow an activation-energy based conduction at high temperatures. The conductivity for nanowires synthesized from 600°C to 2000°C is calculated and is linked to changes in the microstructure using data obtained from SEM, TEM and Raman spectroscopy. The electrical properties of the nanowire are shown to be linked intrinsically to the microstructure and the degree of disorder, which in turn can be controlled to a great extent just by controlling the pyrolysis temperature. This ability to tune the electrical property, specifically conductivity, and map it to the structural changes within the disordered material makes it a candidate material for use in active/passive electronic components, and as versatile transducers for sensors.

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Wiederrecht, Gary P., Thomas P. Dougherty i Keith A. Nelson. "Impulsive Stimulated Raman Scattering Study of Soft Mode Dynamics in Ferroelectric Crystals". W International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/up.1992.tha5.

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Soft Modes, ISRS, and Perovskite Ferroelectrics The dynamics of cooperative ordering in crystals near structural phase transitions have long been elusive. Most picosecond and femtosecond time-resolved measurements have involved rapid laser heating of a sample whose phase transition (e.g. melting) dynamics are then monitored1. In this case many lattice degrees of freedom are excited, and little information is provided about the roles or dynamics of particular lattice motions. In structural phase transitions, the order parameter is described by one or a very few specific ("soft") lattice modes whose motions bring crystalline constituents from their initial positions into their positions in a new crystalline phase. Experimental characterization of the dynamics is possible in some cases through Raman spectroscopy, but often the highly damped character of the soft mode leads to a central peak in the Raman spectrum which cannot be analyzed accurately. In many cases it is not even possible to tell whether the ordering motion is a heavily damped vibration, Debye relaxation, or some combination of the two. This information is essential for understanding the microscopic mechanism of a transition since vibrational or relaxational character is an indication of ionic motion within a single potential energy minimum (i.e. a displacive transition) or hopping between different sites (an order-disorder transition) respectively.

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Aloy, A. S., R. A. Soshnikov, D. B. Lopukh, D. F. Bickford, C. C. Herman, E. W. Holtzsheiter i R. W. Goles. "Vitrification of DOE Simulated Radioactive Waste by Induction-Heated Cold-Crucible Melter Technology". W ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4907.

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Certain waste streams of the US DOE contain radioactive refractory oxides and other components like aluminum zirconium and chromium, which present difficulties during their processing and immobilization. The vitrification of such waste in joule-heated melters at high waste loading is possible only at a temperature exceeding 1150°C. The Khlopin Radium Institute (St.-Petersburg, Russia) jointly with the US Department of Energy has performed a feasibility study on the suitability of the Cold-Crucible Induction Heated Melter (CCIM) technology for the single-stage solidification of a surrogate sludge (C-106/AY-102 HLW Simulant), similar in composition to the High Level Waste (HLW) found at DOE’s Hanford Site (Richland, USA). During the experiments, slurry of simulated sludge and glass formers was metered directly to the CCIM, melted, and the glass product was poured from the melter. The melts were conducted at a mean melt temperature of 1350°C. The experiments produced borosilicate glass wasteforms with a waste oxide loading of 70 weight percent. According to the X-Ray diffraction analysis, the final product had a glass-crystalline structure. The crystalline phase was represented by spinel, (Fe,Mn)Fe2O4, uniformly distributed over the wasteform. The chemical durability of the samples was tested by the Product Consistency Test (PCT), and was considered durable according to the DOE specifications for HLW. In the course of the experiments, data were accumulated on the specific electric power consumption and the throughput of the facility.

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Bogner, U., T. Attenberger i R. Bauer. "Correlations between Dynamical Processes and Electric Field Effects in Perylene/n-Heptane Probed by Persistent Spectral Holes". W Spectral Hole-Burning and Luminescence Line Narrowing: Science and Applications. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/shbl.1992.mb4.

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Persistent spectral hole-burning (PSIIB) and thermally induced hole refilling in the Shpol‘skii system perylene/n-heptane and in the amorphous regions of polyethylene (PE) doped with perylene provides a microscopic model of the physical nature of the asymmetric double-well potentials (ADWP), which are characteristic for amorphous systems and crystalline solids with local disorder [1]. These ADWP have been originally introduced in order to explain anomalous acoustic and thermal properties of amorphous materials by the socalled two level systems, the existence of which is due to tunneling in double-well potentials (DWP) with appropriate parameters. In connection with phonon detection by hole refilling, meassured after irradiation of nanosecond heat pulses, a model for photophysical PSHB was presented which is based on spectral jumps (matrix-shift variations) caused by crossing over the barriers of ADWP [2]. Recently spectral jumps have been observed for single molecules [3].

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Hershberger, Jeff, Oyelayo O. Ajayi, Cinta Lorenzo-Martin, Jules L. Routbort i George R. Fenske. "X-Ray Diagnostics for Scuffing: Application to Phase Transformation in Nickel". W World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63904.

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Through the use of X-ray diffraction (XRD) and other diagnostics, the fundamental physical mechanisms of scuffing are becoming better understood. Peak broadening in the XRD pattern has been analyzed to determine the dislocation structure and crystallite size. Evidence from this technique has led us to conclude that scuffing is an example of adiabatic shear instability, wherein work hardening is exceeded by the thermal softening caused by the work. We are extending this research through scuff testing and XRD of nonferrous materials. For example, members of our team have recently found frictional behavior and surface morphologies consistent with scuffing in single crystals of MgO. Previous work has suggested the use of scuffing as a general method for the formation of metastable phases. Phase identification information available from the XRD data indicated the formation of austenite in scuffed SAE4340 steel, and the present work reports the discovery of a tribologically formed metastable phase in nickel. The formation of this phase was associated with surface roughening and a rapid friction increase of approximately 50%. However, the morphology of the roughened surface indicated abrasion rather than the gross plasticity typical of scuffed surfaces. X-ray diffraction identified the phase as either nickel carbide (Ni3C) or hexagonal nickel, which are similar in structure, and ruled out the presence of crystalline nickel oxides. Analysis of peak widths revealed that the dislocation density in the areas that experienced a higher friction coefficient was lower than that in low-friction areas. This finding is not consistent with dislocation density changes in scuffed steel.

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