Artykuły w czasopismach: „Solid State Physics - Crystallinity”

1

Zeng, Wen, Haojie Lai, Tianyin Chen, Yueheng Lu, Zhihong Liang, Tingting Shi, Ke Chen i in. "Size and crystallinity control of dispersed VO2 particles for modulation of metal–insulator transition temperature and hysteresis". CrystEngComm 21, nr 38 (2019): 5749–56. http://dx.doi.org/10.1039/c9ce01013k.

Pełny tekst źródła

Streszczenie:

Growth mechanism of VO₂ particles with size dependent crystallinity: a solid-state dewetting and pyrolysis synergistic effect. Crystallinity, strain and defects optimize and modulate the MIT behavior of VO₂ particles.

Style APA, Harvard, Vancouver, ISO itp.

2

Murakami, Fabio S., Karen L. Lang, Cassiana Mendes, Ariane P. Cruz, Marco A. S. Carvalho Filho i Marcos A. S. Silva. "Physico-chemical solid-state characterization of omeprazole sodium: Thermal, spectroscopic and crystallinity studies". Journal of Pharmaceutical and Biomedical Analysis 49, nr 1 (styczeń 2009): 72–80. http://dx.doi.org/10.1016/j.jpba.2008.10.005.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

3

Opsomer, K., D. Deduytsche, C. Detavernier, R. L. Van Meirhaeghe, A. Lauwers, K. Maex i C. Lavoie. "Influence of Ge substrate crystallinity on Co germanide formation in solid-state reactions". Applied Physics Letters 90, nr 3 (15.01.2007): 031906. http://dx.doi.org/10.1063/1.2431781.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

4

Li, Zhen, Li Yu, Liqiang Zheng i Fei Geng. "Studies on crystallinity state of puerarin loaded solid lipid nanoparticles prepared by double emulsion method". Journal of Thermal Analysis and Calorimetry 99, nr 2 (19.06.2009): 689–93. http://dx.doi.org/10.1007/s10973-009-0127-z.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

5

Mendes, R. A., G. Bannach, E. Y. Ionashiro i M. Ionashiro. "Synthesis, characterization and thermal studies of solid state 4-methylbenzylidenepyruvate of some trivalent metal ions". Eclética Química 30, nr 2 (2005): 25–30. http://dx.doi.org/10.1590/s0100-46702005000200003.

Pełny tekst źródła

Streszczenie:

Solid state compounds of 4-methylbenzylidenepyruvate with Al(III), Ga(III), In(III) and Sc(III) have been synthesized. Complexometry, X-ray powder diffractometry, infrared spectroscopy and simultaneous thermogravimetry-differential thermal analysis (TG-DTA) have been used to characterize and to study the thermal behavior of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition of these compounds.

Style APA, Harvard, Vancouver, ISO itp.

6

Rodríguez-Carrillo, Cristina, Juan Torres García, Miriam Benítez, Jamal El Haskouri, Pedro Amorós i Jose V. Ros-Lis. "Batch and Flow Synthesis of CeO2 Nanomaterials Using Solid-State Microwave Generators". Molecules 27, nr 9 (22.04.2022): 2712. http://dx.doi.org/10.3390/molecules27092712.

Pełny tekst źródła

Streszczenie:

Microwave-assisted synthesis in combination with flow synthesis offers an interesting approach to develop faster and more sustainable procedures for the preparation of homogeneous nanomaterials. Recently, solid-state generators of microwaves appeared as a tool with improved control over power and frequency. Cerium oxide, despite its excellent catalytic activity, has not been prepared before using solid-state generators or microwave-assisted flow chemistry. We report a procedure for the preparation of nanoparticulated CeO2 (around 4 nm) under 2.45 GHz microwaves in only 30 s. The materials are further calcined at 800 °C to increase particle size, with a better defined particle size and crystallinity. The procedure was tested in batch at pH 11 and 12 and diverse potencies, and the products were characterized by TEM, XRD, DLS, and N2 adsorption–desorption isotherms. The materials were similar at the diverse pH values and potencies. XRD confirms the crystallinity of the CeO2 material with a fluorite-like structure. They are composed of particles around 40 nm that aggregate as structures of around 100 nm. The procedure was successfully adapted to flow synthesis, obtaining materials with structure and properties equivalent to batch synthesis. The batch and flow materials offer peroxidase properties, opening the door for their use as ROS scavengers.

Style APA, Harvard, Vancouver, ISO itp.

7

Bannach, G., E. Schnitzler i M. Ionashiro. "Synthesis, characterization and thermal behaviour of solid state compounds of 2-chlorobenzylidenepyruvate with trivalent aluminium, gallium, indium and scandium metals". Eclética Química 28, nr 1 (2003): 19–24. http://dx.doi.org/10.1590/s0100-46702003000100002.

Pełny tekst źródła

Streszczenie:

Solid state compounds M-2-Cl-BP, where 2-Cl-BP is 2-chlorobenzylidenepyruvate and M represents Al, Ga, In, and Sc were prepared. X-ray powder diffractometry, infrared spectroscopy and simultaneous thermogravimetry-differential thermal analysis (TG-DTA), have been used to characterize and to study the thermal behavior of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition of the compounds.

Style APA, Harvard, Vancouver, ISO itp.

8

Scharf, T. W., S. V. Prasad, T. M. Mayer, R. S. Goeke i M. T. Dugger. "Atomic layer deposition of tungsten disulphide solid lubricant thin films". Journal of Materials Research 19, nr 12 (1.12.2004): 3443–46. http://dx.doi.org/10.1557/jmr.2004.0459.

Pełny tekst źródła

Streszczenie:

The synthesis and characterization of crystalline tungsten disulphide (WS2) solid lubricant thin films grown by atomic layer deposition (ALD) using WF6 and H2S gas precursors was studied. A new catalytic route was established to promote nucleation and growth of WS2 films on silicon surfaces with native oxide. Scanning electron microscopy with energy dispersive spectroscopy and Raman spectroscopy were used to determine the film morphology, composition, and crystallinity. The films exhibited solid lubricating behavior with a steady-state friction coefficient of 0.04 in a dry nitrogen environment.

Style APA, Harvard, Vancouver, ISO itp.

9

Peng, Zhi-Qing, Rong Chen i Wen-Lin Feng. "Photoluminescence Properties of Ca3Si2O7: Pr3+ Orange-Red Phosphors Prepared by High-Temperature Solid-State Method". Zeitschrift für Naturforschung A 73, nr 6 (27.06.2018): 555–58. http://dx.doi.org/10.1515/zna-2018-0050.

Pełny tekst źródła

Streszczenie:

AbstractNovel luminescent materials Ca3-xSi2O7: xPr3+ were successfully prepared by the high-temperature solid-state method. The crystal structure, morphology, and optical spectrum were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectroscopy, respectively. The XRD patterns of the samples indicate that the crystal structure is monoclinic symmetry. The SEM shows that the selected sample has good crystallinity although its appearance is irregular and scalelike. The peak of the excitation spectrum of the sample is located at around 449 nm, corresponding to 3H4→3P2 transition of Pr3+. The peak of the emission spectrum of the sample is situated at around 612 nm which is attributed to 3P0→3H6 transition of Pr3+, and the colour is orange-red. The optimum concentration for Pr3+ replaced Ca2+ sites in Ca3Si2O7: Pr3+ is 0.75 mol%. The lifetime (8.48 μs) of a typical sample (Ca2.9925Pr0.0075)Si2O7 is obtained. It reveals that orange-red phosphors Ca3-xSi2O7: xPr3+ possess remarkable optical properties and can be used in white light emitting devices.

Style APA, Harvard, Vancouver, ISO itp.

10

Shaban, A. H., L. A. Mohammed, H. S. Hussein i K. A. Jasim. "The structural properties of Y1-XLaXBa4Cu7O15+ δ superconductor compound". Digest Journal of Nanomaterials and Biostructures 17, nr 2 (kwiecień 2022): 519–25. http://dx.doi.org/10.15251/djnb.2022.172.519.

Pełny tekst źródła

Streszczenie:

The eff ect of partial substitution for lanthanum (La) on the structural properties of the compound Y1-xLaxBa4Cu7O15+δ were studied. The variation of (x) are x=0.1, 0.2 and 0.3, which was synthesized by solid state reaction method. The mixed powder was pressed with pressure (7 ton / cm2) as a disc (1.5 cm) diameter and a thickness of (0.25 to 0.3 cm). The samples were sintering by 120 °C / hour with a changing rate from room temperature to 850 ° C through 72 hours. XRD analysis using to calculate crystal size, strain and degree of crystallinity. It was found all samples have orthorhombic structure and change of structure with increasing lanthanum concentration. It was shown that the change lanthanum concentrations of all our samples produce a change in the crystal size, strain, degree of crystallinity and lattice parameters.

Style APA, Harvard, Vancouver, ISO itp.

11

Sohib, Ahmad, Jotti Karunawan, Citra Deliana Dewi Sundari, Octia Floweri i Ferry Iskandar. "Rietveld study on the effect of pelletizing and sintering towards the structural evolution of Li_1.3Al_0.3Ti_1.7(PO₄)₃". Journal of Physics: Conference Series 2243, nr 1 (1.06.2022): 012044. http://dx.doi.org/10.1088/1742-6596/2243/1/012044.

Pełny tekst źródła

Streszczenie:

Abstract Lithium aluminium titanium phosphate, Li1.3Al0.3Ti1.7(PO4)3 (LATP), is a highly potential material for solid electrolyte (SE) in an all-solid-state battery (ASSB) thanks to its superior ionic conductivity. The crystallinity of the material plays an important role in determining the ionic conductivity, ensuring the excellent performance of ASSB. To be applied in the ASSB, LATP should be pressed into a disc and then sintered at a high temperature to obtain the dense disk. This research aims to investigate the effect of pelletizing and sintering on the crystallinity of LATP. LATP powder was synthesized via a sol-gel method and mechanically pressed into pellets and sintered. Morphology and structural features of the LATP samples (powder and pelletized samples) were characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The results demonstrated that the particle size of LATP in the pelletized samples was larger than the powder one. This morphology possibly contributed to the lower internal resistance of LATP and, therefore, its higher ionic conductivity. Rietveld refinement analysis showed that the crystalline properties of LATP changed after pelletizing and sintering treatment. This research demonstrated the importance of well consideration of pelletizing and sintering process to achieve high ionic conductivity of LATP.

Style APA, Harvard, Vancouver, ISO itp.

12

McElderry, John-David P., Peizhi Zhu, Kamal H. Mroue, Jiadi Xu, Barbara Pavan, Ming Fang, Guisheng Zhao i in. "Crystallinity and compositional changes in carbonated apatites: Evidence from 31P solid-state NMR, Raman, and AFM analysis". Journal of Solid State Chemistry 206 (październik 2013): 192–98. http://dx.doi.org/10.1016/j.jssc.2013.08.011.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

13

Lookman, Turab, i Peter Littlewood. "Nanoscale Heterogeneity in Functional Materials". MRS Bulletin 34, nr 11 (listopad 2009): 822–31. http://dx.doi.org/10.1557/mrs2009.232.

Pełny tekst źródła

Streszczenie:

AbstractThe physical properties that make “functional” materials worthy of their moniker frequently arise because of a phase transition that establishes a new kind of order as the material is cooled from a parent state. Such ordered states include ferroelectrics, ferromagnets, and structurally ordered martensites; because these states all break an orientational symmetry, and it is rare that one can produce the conditions for single domain crystallinity, the observed configuration is generally heterogeneous. However, the conditions under which domain structures form are highly constrained, especially by elastic interactions within a solid; consequently, the observed structures are far from fully random, even if disorder is present. Often the structure of the heterogeneity is important to the function, as in shape-memory alloys. Increasingly, we are surprised to discover new phases inside solids that are themselves a heterogeneous modulation of their parents.

Style APA, Harvard, Vancouver, ISO itp.

14

Ferrer-Ugalde, Albert, Arántzazu González-Campo, José Giner Planas, Clara Viñas, Francesc Teixidor, Isabel M. Sáez i Rosario Núñez. "Tuning the Liquid Crystallinity of Cholesteryl-o-Carborane Dyads: Synthesis, Structure, Photoluminescence, and Mesomorphic Properties". Crystals 11, nr 2 (28.01.2021): 133. http://dx.doi.org/10.3390/cryst11020133.

Pełny tekst źródła

Streszczenie:

A set of mesomorphic materials in which the o-carborane cluster is covalently bonded to a cholesteryl benzoate moiety (mesogen group) through a suitably designed linker is described. The olefin cross-metathesis between appropriately functionalized styrenyl-o-carborane derivatives and a terminal alkenyl cholesteryl benzoate mesogen (all type I terminal olefins) leads to the desired trans-regioisomer, which is the best-suited configuration to obtain mesomorphic properties in the final materials. The introduction of different substituents (R = H (M2), Me (M3), or Ph (M4)) to one of the carbon atoms of the o-carborane cluster (Ccluster) enables the tailoring of liquid crystalline properties. Compounds M2 and M3 show the chiral nematic (N*) phase, whereas M4 do not show liquid crystal behavior. Weaker intermolecular interactions in the solid M3 with respect to those in M2 may allow the liquid crystallinity in M3 to be expressed as enantiotropic behavior, whereas breaking the stronger intermolecular interaction in the solid state of M2 leads directly to the isotropic state, resulting in monotropic behavior. Remarkably, M3 also displays the blue phase, which was observed neither in the chiral nematic precursor nor in the styrenyl-cholesterol model (M5) without an o-carborane cluster, which suggests that the presence of the cluster plays a role in stabilizing this highly twisted chiral phase. In the carborane-containing mesogens (M2 and M3), the o-carborane cluster can be incorporated without destroying the helical organization of the mesophase.

Style APA, Harvard, Vancouver, ISO itp.

15

POKHREL, S., S. SHAH i H. S. ADHIKARI. "Synthesis and Characterization of Chitosan from Prawn Shells and Study of Its Effects on Weight Loss of Myrica esculenta Fruits". Asian Journal of Chemistry 33, nr 2 (2021): 299–306. http://dx.doi.org/10.14233/ajchem.2021.22980.

Pełny tekst źródła

Streszczenie:

In this work, chitin and chitosan were obtained from prawn shell wastages by chemical treatment method. Structural characterization of chitin and chitosan by FTIR, X-ray photoelectron spectroscopy (XPS) and 13C NMR clearly showed the formation of chitosan from chitin. The physico-chemical properties of chitosan viz. molecular weight, moisture content, ash content and degree of deacetylation (DD) were analyzed. The optimum condition of deacetylation process to obtain chitosan from chitin was analyzed. The FTIR spectra showed the characteristic peaks corresponding to hydroxy, acetamido and amino functionalities of chitosan obtained from partial deacetylation of chitin and the solid state 13C NMR showed the formation of chitosan with characteristic peaks. XRD showed the shifting of crystallinity phases showing more crystallinity of chitin than chitosan. XPS spectrum of prepared chitin with the peaks corresponding to N, C and O binding energy was analogous to the standard. The effect of chitosan coating in extension of postharvest life of Kaphal (Myrica esculenta) fruits was investigated and chitosan coating was observed to have a potential to prolong storage life, control decay and weight loss.

Style APA, Harvard, Vancouver, ISO itp.

16

Bannach, G., E. Schnitzler, C. B. Melios i M. Ionashiro. "Synthesis and thermal studies of solid state 2-chloro-benzylidenepyruvic acid and its compounds with sodium, aluminium (III), gallium (III) and indium (III) cations". Eclética Química 29, nr 1 (2004): 31–40. http://dx.doi.org/10.1590/s0100-46702004000100004.

Pełny tekst źródła

Streszczenie:

The synthesis of sodium 2-chlorobenzylidenepyruvate and its corresponding acid as well as binary, binary together with it's acid or hydroxo-2-chorobenzylidenepyruvate of aluminium (III), gallium (III) and indium (III), were isolated. Chemical analysis, thermogravimetry, derivative thermogravimetry (TG/DTG), simultaneous thermogravimetry-differential thermal analysis (TG-DTA) and X-ray powder diffractometry have been employed to characterize and to study the thermal behaviour of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition.

Style APA, Harvard, Vancouver, ISO itp.

17

De Silva, Thenahandi Prasanthi Deepthika, Sang Gil Youm, Frank R. Fronczek, Girija Sahasrabudhe, Evgueni E. Nesterov i Isiah M. Warner. "Pyrene-Benzimidazole Derivatives as Novel Blue Emitters for OLEDs". Molecules 26, nr 21 (28.10.2021): 6523. http://dx.doi.org/10.3390/molecules26216523.

Pełny tekst źródła

Streszczenie:

Three novel small organic heterocyclic compounds: 2-(1,2-diphenyl)-1H-benzimidazole-7-tert-butylpyrene (compound A), 1,3-di(1,2-diphenyl)-1H-benzimidazole-7-tert-butylpyrene (compound B), and 1,3,6,8-tetra(1,2-diphenyl)-1H-benzimidazolepyrene (compound C) were synthesized and characterized for possible applications as blue OLED emitters. The specific molecular design targeted decreasing intermolecular aggregation and disrupting crystallinity in the solid-state, in order to reduce dye aggregation, and thus obtain efficient pure blue photo- and electroluminescence. Accordingly, the new compounds displayed reasonably high spectral purity in both solution- and solid-states with average CIE coordinates of (0.160 ± 0.005, 0.029 ± 0.009) in solution and (0.152 ± 0.007, 0.126 ± 0.005) in solid-state. These compounds showed a systematic decrease in degree of crystallinity and intermolecular aggregation due to increasing steric hindrance, as revealed using powder X-ray diffraction analysis and spectroscopic studies. An organic light-emitting diode (OLED) prototype fabricated using compound B as the non-doped emissive layer displayed an external quantum efficiency (EQE) of 0.35 (±0.04)% and luminance 100 (±6) cd m−2 at 5.5 V with an essentially pure blue electroluminescence corresponding to CIE coordinates of (0.1482, 0.1300). The highest EQE observed from this OLED prototype was 4.3 (±0.3)% at 3.5 V, and the highest luminance of 290 (±10) cd m−2 at 7.5 V. These values were found comparable to characteristics of the best pure blue OLED devices based on simple fluorescent small-molecule organic chromophores.

Style APA, Harvard, Vancouver, ISO itp.

18

Barrera, Gabriele, Federica Celegato, Matteo Cialone, Marco Coïsson, Paola Rizzi i Paola Tiberto. "Effect of the Substrate Crystallinity on Morphological and Magnetic Properties of Fe70Pd30 Nanoparticles Obtained by the Solid-State Dewetting". Sensors 21, nr 21 (8.11.2021): 7420. http://dx.doi.org/10.3390/s21217420.

Pełny tekst źródła

Streszczenie:

Advances in nanofabrication techniques are undoubtedly needed to obtain nanostructured magnetic materials with physical and chemical properties matching the pressing and relentless technological demands of sensors. Solid-state dewetting is known to be a low-cost and “top-down” nanofabrication technique able to induce a controlled morphological transformation of a continuous thin film into an ordered nanoparticle array. Here, magnetic Fe70Pd30 thin film with 30 nm thickness is deposited by the co-sputtering technique on a monocrystalline (MgO) or amorphous (Si3N4) substrate and, subsequently, annealed to promote the dewetting process. The different substrate properties are able to tune the activation thermal energy of the dewetting process, which can be tuned by depositing on substrates with different microstructures. In this way, it is possible to tailor the final morphology of FePd nanoparticles as observed by advanced microscopy techniques (SEM and AFM). The average size and height of the nanoparticles are in the ranges 150–300 nm and 150–200 nm, respectively. Moreover, the induced spatial confinement of magnetic materials in almost-spherical nanoparticles strongly affects the magnetic properties as observed by in-plane and out-of-plane hysteresis loops. Magnetization reversal in dewetted FePd nanoparticles is mainly characterized by a rotational mechanism leading to a slower approach to saturation and smaller value of the magnetic susceptibility than the as-deposited thin film.

Style APA, Harvard, Vancouver, ISO itp.

19

Poulhazan, Alexandre, Alexandre Arnold, Dror Warschawski i Isabelle Marcotte. "Unambiguous Ex Situ and in Cell 2D 13C Solid-State NMR Characterization of Starch and Its Constituents". International Journal of Molecular Sciences 19, nr 12 (30.11.2018): 3817. http://dx.doi.org/10.3390/ijms19123817.

Pełny tekst źródła

Streszczenie:

Starch is the most abundant energy storage molecule in plants and is an essential part of the human diet. This glucose polymer is composed of amorphous and crystalline domains in different forms (A and B types) with specific physicochemical properties that determine its bioavailability for an organism, as well as its value in the food industry. Using two-dimensional (2D) high resolution solid-state nuclear magnetic resonance (SS-NMR) on 13C-labelled starches that were obtained from Chlamydomonas reinhardtii microalgae, we established a complete and unambiguous assignment for starch and its constituents (amylopectin and amylose) in the two crystalline forms and in the amorphous state. We also assigned so far unreported non-reducing end groups and assessed starch chain length, crystallinity and amylose content. Starch was then characterized in situ, i.e., by 13C solid-state NMR of intact microalgal cells. Our in-cell methodology also enabled the identification of the effect of nitrogen starvation on starch metabolism. This work shows how solid-state NMR can enable the identification of starch structure, chemical modifications and biosynthesis in situ in intact microorganisms, eliminating time consuming and potentially altering purification steps.

Style APA, Harvard, Vancouver, ISO itp.

20

JUNG, YE RAN, HYUN KYOUNG YANG, BYUNG KEE MOON, BYUNG CHUN CHOI, JUNG HYUN JEONG, JUNG HWAN KIM, JONG SEONG BAE i EUI DUCK JEONG. "SOL–GEL COMBUSTION SYNTHESIS AND LUMINESCENT PROPERTIES OF NANOCRYSTALLINE Y3Al5O12:Eu3+ PHOSPHORS". Surface Review and Letters 17, nr 01 (luty 2010): 73–79. http://dx.doi.org/10.1142/s0218625x10013850.

Pełny tekst źródła

Streszczenie:

Nanosized YAG:Eu 3+ powder samples were synthesized by using co-precipitation method and combining stoichiometric ratios of Y ( NO 3)3 · 6 H 2 O , Eu ( NO 3)3 · 5 H 2 O , Al(OR) 3. After sintering at the temperature of 900°C for 3 h, YAG:Eu 3+ nanoparticles with single phase were obtained. In comparison with the conventional solid-state reaction process, this sol–gel process not only decreased the temperature required for synthesizing YAG:Eu 3+ powder, but also reduced their particle size to the nanometer range. The crystallinity, surface morphology and photoluminescent characteristics of phosphors were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectrophotometer, respectively. The size of the nanocrystalline materials was found to increase from 33.66 to 51.70 nm with the annealing temperature increasing from 900° to 1100°C. The photoluminescence spectra shows the emissions radiated by the transitions from 5 D 0 excited states to 7 F J (J = 1, 2) states of Eu 3+ ions. The crystallinity, surface morphology and photoluminescence spectra of phosphors were highly dependent on the sintering temperature.

Style APA, Harvard, Vancouver, ISO itp.

21

Chen, Hsiang-Chen, Hung-Chi Chou, Jeffrey C. S. Wu i Hsin-Yu Lin. "Sol-gel prepared InTaO4 and its photocatalytic characteristics". Journal of Materials Research 23, nr 5 (maj 2008): 1364–70. http://dx.doi.org/10.1557/jmr.2008.0172.

Pełny tekst źródła

Streszczenie:

InTaO4 is an efficient visible-light photocatalyst, which used to be synthesized by solid-state fusion at over 1100 °C. However, irregular morphology and severe agglomeration of particles were acquired due to nonuniform fusion of solid precursors. In this study, InTaO4 was synthesized by two sol-gel routes, the thermal hydrolysis and esterification methods. The precursors were indium (III) nitrate pentahydrate [In(NO3)3] and tantalum(V) butoxide [Ta(OC4H9)5] dissolved in solutions. The InTaO4 powders with a uniform grain size of 17.7 nm were successfully synthesized using the esterification method at a calcination temperature of 950 °C. A uniform InTaO4 thin film nearly 40 nm thick formed on an optical fiber at 1100 °C using the sol prepared by the esterification method. For the first time, InTaO4 was evaluated by the photocatalytic activity of CO2 photo reduction, which was conducted in aqueous solution under visible light irradiation. Cocatalyst NiO was loaded on the surface of InTaO4 to further enhance the methanol yield. The methanol yields of NiO/InTaO4 by esterification method were significantly higher than those by solid-state fusion. The esterification method provided homogeneous mixing of Ta(OC4H9)5 and In(NO3)3, resulting in nano-sized InTaO4 with uniform crystallinity and superior photocatalytic activity.

Style APA, Harvard, Vancouver, ISO itp.

22

Bentley, Flor Estefany, Renaud Passieux, Laurent David i Anayancy Osorio-Madrazo. "Pure Chitosan Biomedical Textile Fibers from Mixtures of Low- and High-Molecular Weight Bidisperse Polymer Solutions: Processing and Understanding of Microstructure–Mechanical Properties’ Relationship". International Journal of Molecular Sciences 23, nr 9 (26.04.2022): 4767. http://dx.doi.org/10.3390/ijms23094767.

Pełny tekst źródła

Streszczenie:

Natural polymers, as extracted from biomass, may exhibit large macromolecular polydispersity. We investigated the impact of low molar mass chitosan (LMW, DPw~115) on the properties of chitosan fibers obtained by wet spinning of chitosan solutions with bimodal distributions of molar masses. The fiber crystallinity index (CrI) was assessed by synchrotron X-ray diffraction and the mechanical properties were obtained by uniaxial tensile tests. The LMW chitosan showed to slightly increase the crystallinity index in films which were initially processed from the bimodal molar mass chitosan solutions, as a result of increased molecular mobility and possible crystal nucleating effects. Nevertheless, the CrI remained almost constant or slightly decreased in stretched fibers at increasing content of LMW chitosan in the bidisperse chitosan collodion. The ultimate mechanical properties of fibers were altered by the addition of LMW chitosan as a result of a decrease of entanglement density and chain orientation in the solid state. An increase of crystallinity might not be expected from LMW chitosan with a still relatively high degree of polymerization (DPw ≥ 115). Instead, different nucleation agents—either smaller molecules or nanoparticles—should be used to improve the mechanical properties of chitosan fibers for textile applications.

Style APA, Harvard, Vancouver, ISO itp.

23

Bentley, Flor Estefany, Renaud Passieux, Laurent David i Anayancy Osorio-Madrazo. "Pure Chitosan Biomedical Textile Fibers from Mixtures of Low- and High-Molecular Weight Bidisperse Polymer Solutions: Processing and Understanding of Microstructure–Mechanical Properties’ Relationship". International Journal of Molecular Sciences 23, nr 9 (26.04.2022): 4767. http://dx.doi.org/10.3390/ijms23094767.

Pełny tekst źródła

Streszczenie:

Natural polymers, as extracted from biomass, may exhibit large macromolecular polydispersity. We investigated the impact of low molar mass chitosan (LMW, DPw~115) on the properties of chitosan fibers obtained by wet spinning of chitosan solutions with bimodal distributions of molar masses. The fiber crystallinity index (CrI) was assessed by synchrotron X-ray diffraction and the mechanical properties were obtained by uniaxial tensile tests. The LMW chitosan showed to slightly increase the crystallinity index in films which were initially processed from the bimodal molar mass chitosan solutions, as a result of increased molecular mobility and possible crystal nucleating effects. Nevertheless, the CrI remained almost constant or slightly decreased in stretched fibers at increasing content of LMW chitosan in the bidisperse chitosan collodion. The ultimate mechanical properties of fibers were altered by the addition of LMW chitosan as a result of a decrease of entanglement density and chain orientation in the solid state. An increase of crystallinity might not be expected from LMW chitosan with a still relatively high degree of polymerization (DPw ≥ 115). Instead, different nucleation agents—either smaller molecules or nanoparticles—should be used to improve the mechanical properties of chitosan fibers for textile applications.

Style APA, Harvard, Vancouver, ISO itp.

24

Cao, Zhanzhi, Chunhua Liu, Yunxia Huang, Ya Gao, Yuan Wang, Zhimin Li, Yangxi Yan i Maolin Zhang. "Oxygen-vacancy-rich NiCo2O4 nanoneedles electrode with poor crystallinity for high energy density all-solid-state symmetric supercapacitors". Journal of Power Sources 449 (luty 2020): 227571. http://dx.doi.org/10.1016/j.jpowsour.2019.227571.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

25

Pajor, Kamil, Łukasz Pajchel, Anna Zgadzaj, Urszula Piotrowska i Joanna Kolmas. "Modifications of Hydroxyapatite by Gallium and Silver Ions—Physicochemical Characterization, Cytotoxicity and Antibacterial Evaluation". International Journal of Molecular Sciences 21, nr 14 (15.07.2020): 5006. http://dx.doi.org/10.3390/ijms21145006.

Pełny tekst źródła

Streszczenie:

Hydroxyapatite (HA) powders enriched with silver or gallium ions or both were synthesized by two different routes: standard precipitation and the solid-state method. The powders were characterized by using several methods: inductively coupled plasma optical emission spectrometry (ICP-OES), powder X-ray diffractometry (PXRD), transmission electron microscopy (TEM), infrared spectroscopy (FT-IR) and solid-state nuclear magnetic resonance spectroscopy (ssNMR). The effects of enrichment of the HAs in Ag+ or Ga3+ or both on in vitro cytotoxicity and microbiological activity were discussed. PXRD experiments showed that the samples obtained by the wet method consisted of single-phase nanocrystalline HA, while the samples prepared via the solid-state method are microcrystalline with a small amount of calcium oxide. The introduction of higher amounts of silver ions was found to be more effective than enriching HA with small amounts of Ag+. Gallium and silver ions were found not to affect the lattice parameters. Ga3+ affected the crystallinity of the samples as well as the content of structural hydroxyl groups. Among samples synthesized by the wet method, only one (5Ag-HAw) was cytotoxic, whereas all Ga-containing samples obtained by the dry method showed cytotoxicity. In the preliminary antimicrobial test all the materials containing “foreign” ions showed high antibacterial activity.

Style APA, Harvard, Vancouver, ISO itp.

26

Sun, Xianmiao, Qiong Sun, Yang Li, Lina Sui i Lifeng Dong. "Effects of calcination treatment on the morphology, crystallinity, and photoelectric properties of all-solid-state dye-sensitized solar cells assembled by TiO2 nanorod arrays". Physical Chemistry Chemical Physics 15, nr 42 (2013): 18716. http://dx.doi.org/10.1039/c3cp51941d.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

27

Raza, Saleem, Sikandar Khan, Ata Ur Rahman, Muslim Raza i Fazal Wahid. "Enhancement of Physico-chemical and Biological Activities of Antibiotic Cephradine by Gamma Irradiation". Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences 65, nr 1 (22.02.2022): 1–8. http://dx.doi.org/10.52763/pjsir.phys.sci.65.1.2022.1.8.

Pełny tekst źródła

Streszczenie:

Radiation based sterilization is a common tool for microbial inactivation in different products on a commercial scale. The objective of the current study was to determine the effect of gamma radiation on cephradine antibiotic in the solid-state to enhance its biological response. Cephradine drug in powder form was treated with different doses (25, 50, 75, 100 and 125 kGy) of the cobalt-60 source in a Gamma cell-220 at a current rate of 8.5 gray/h. The effect of radiation doses on antibiotic was assessed with the help of different analytical techniques such as FT-IR, UV, XRD, SEM and HPLC. The UV spectra of radiated cephradine show some changes in the absorption peak by increasing the intensity of radiations while only slight changes were observed in the other peaks. The crystallinity of antibiotics was tested by the XRD and SEM, it shows a little morphological change. The FT-IR data disclosed significant changes in the absorption bands. The HPLC analysis showed reports an insignificant change which revealed that the radiolytic products are not formed. The radiated cephradine exposes a remarkable antibacterial activity against bacteria; indicating the enhancement of a biological response. In summary, a slight change was observed in cephradine drug with the radiation but the drug was chemically stable.

Style APA, Harvard, Vancouver, ISO itp.

28

Oliveira, Filipa M., Teresa G. Nunes, Nadya V. Dencheva i Zlatan Z. Denchev. "Structure and Molecular Dynamics in Metal-Containing Polyamide 6 Microparticles". Crystals 12, nr 11 (5.11.2022): 1579. http://dx.doi.org/10.3390/cryst12111579.

Pełny tekst źródła

Streszczenie:

Polymer microparticles are used in additive manufacturing, separation and purification devices, biocatalysis, or for the recognition of biomolecules. This study reports on the effect of metal fillers on the structure and molecular dynamics of polyamide 6 (PA6) microparticles (MPs) containing up to 19 wt.% of Al, Cu, or Mg. These hybrid MPs are synthesized via reactive microencapsulation by anionic ring-opening polymerization in solution, in the presence of the metal filler. 13C high-resolution solid-state NMR (ssNMR) spectroscopy is employed as the primary characterization method using magic angle spinning (MAS) and cross-polarization (CP)/MAS. Depending on the metal filler, the ssNMR crystallinity index of the MP varies between 39–50%, as determined by deconvolution of the 13C MAS and CP/MAS spectra. These values correlate very well with the crystallinity derived from thermal or X-ray diffraction data. The molecular dynamics study on PA6 and Cu-containing MP shows similar mobility of carbon nuclei in the kHz, but not in the MHz frequency ranges. The paramagnetic Al and Mg have an observable effect on the relaxation; however, conclusions regarding the PA6 carbon motions cannot be unequivocally made. These results are useful in the preparation of hybrid microparticles with customized structures and magneto-electrical properties.

Style APA, Harvard, Vancouver, ISO itp.

29

Speranza, Vito, Rita Salomone i Roberto Pantani. "Effects of Pressure and Cooling Rates on Crystallization Behavior and Morphology of Isotactic Polypropylene". Crystals 13, nr 6 (8.06.2023): 922. http://dx.doi.org/10.3390/cryst13060922.

Pełny tekst źródła

Streszczenie:

Isotactic Polypropylene (iPP) is a widely used polymer due to its excellent mechanical and thermal properties, as well as its chemical resistance. The crystallization behavior of polypropylene is influenced by several factors, such as temperature, cooling rate, and pressure. The effect of pressure is significant for both scientific and technological points of view, since in important industrial processing techniques the polymer solidifies under high pressures. In this paper, the study of the effect of pressure on the crystallization kinetics of iPP was conducted using a dilatometer in the pressure range from 100 to 600 bar and under two cooling rates: 0.1 and 1 °C/s. The morphology of the samples was characterized using DSC, optical microscopy, and X-ray diffraction. The results showed that pressure had a larger effect on specific volume changes at higher temperatures (in the melt state) than at lower temperatures (in the solid state). The polymer crystallization, which determined the transition between the melt and solid state, occurred at higher temperatures with increasing pressure. The cooling rate affected the crystallization process, with higher cooling rates leading to crystallization at lower temperatures. The size of the spherulites decreased with increasing cooling rates. The crystallinity evolution curves showed a linear relationship between the crystallization temperature and pressure. The study used a Kolmogoroff–Avrami–Evans model to describe the evolution into isotropic structures, and the predictions of the model accurately described the effect of pressure and cooling rates on the final spherulite radii.

Style APA, Harvard, Vancouver, ISO itp.

30

Sarvi, Ali, i Farhad Sharif. "Physical gelation process as direct evidence for crystallization behavior of isotactic polypropylene/clay composites". Journal of Thermoplastic Composite Materials 29, nr 12 (4.08.2016): 1656–66. http://dx.doi.org/10.1177/0892705715583176.

Pełny tekst źródła

Streszczenie:

Early stage crystallization kinetics of polypropylene (PP)/clay composites is studied using rheometery. Relaxation modulus of composites is measured at low frequencies near liquid–solid transition. Small amplitude oscillating shear flow is applied at low frequencies to obtain relaxation modulus. Relaxation modulus of polymeric materials at the liquid–solid transition follows [Formula: see text], at long times ( λ < t < ∞), where λ is the time to crossover to a different relaxation regime, s is the gel stiffness, and n is the relaxation exponent. Inverse quenching technique is then employed to retain degree of crystallization while rheological measurements are made. Lower gel time is observed as clay concentration increased, indicating the formation of more nuclei. An improvement to Avrami’s equation is proposed to predict crystallization kinetics for PP/clay composites. There is a good agreement between predicted relative crystallinity values and empirical values.

Style APA, Harvard, Vancouver, ISO itp.

31

Lu, Guozhong, Xuelei Li, Zhengyu Wang, Dawei Song, Hongzhou Zhang, Chunliang Li, Lianqi Zhang i Lingyun Zhu. "Enhanced electrochemical performances of LiCoO2 cathode for all-solid-state lithium batteries by regulating crystallinity and composition of coating layer". Journal of Power Sources 468 (sierpień 2020): 228372. http://dx.doi.org/10.1016/j.jpowsour.2020.228372.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

32

Alharthi, Fahad, Rizwan Wahab, Salim Manoharadas, Basel F. Alrayes i Naushad Ahmad. "Effect of Preparation Method and Ni2+ Substitution on the Structural, Thermal, and Optical Properties of Nanocrystalline Lanthanum Zirconate Pyrochlore". Crystals 11, nr 12 (26.11.2021): 1463. http://dx.doi.org/10.3390/cryst11121463.

Pełny tekst źródła

Streszczenie:

In order to establish the effective application of materials in a particular area, it is important to first investigate the physical and chemical properties, such as the crystallinity, structure, and the optical and surface properties. The objective of the present study is to fabricate thermally stable pyrochlore oxides, namely, lanthanum zirconate (La2Zr2O7, LZ) and Ni-doped lanthanum zirconate (La2Zr1.5Ni0.5O7, LZN) by the solid-state and sol-gel methods. The effects of the preparation and substitution of Zr4+ by Ni2+ for the resulting nanocrystalline samples were characterized in terms of structure, purity, porosity, the thermal and optical properties, and photoluminescence by different techniques: XRD, FT-IR, BET, EDS, TG-DTG, UV-Vis-DRS, and PL. The XRD results confirm that the pyrochlores prepared via the sol-gel method (LZ-sg and LZN-sg) had a cubic unit-cell lattice, whereas the solid-state method (LZ-s and LZN-s) had impurities of the oxides. The XRD patterns, LZ-sg and LZN-sg, were further treated with the Rietveld technique. The textural measurements reveal that LZ-sg had a higher BET surface area compared to LZN-sg. In addition, the substitution of Zr4+ by the Ni2+ ion provides rational evidence for the improvement in the oxygen mobility, as well as the optical and photoluminescence properties through the lowering of the optical band energy and the electron–hole pairs.

Style APA, Harvard, Vancouver, ISO itp.

33

Xie, Xiangqun, Zhenguo Yang, Ruiming Ren i Leon L. Shaw. "Solid state 29Si magic angle spinning NMR: investigation of bond formation and crystallinity of silicon and graphite powder mixtures during high energy milling". Materials Science and Engineering: A 255, nr 1-2 (październik 1998): 39–48. http://dx.doi.org/10.1016/s0921-5093(98)00782-5.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

34

Mallick, Priyambada, S. K. Biswal, S. K. Satpathy i Banarji Behera. "Structural, electrical, and thermistor behavior of BiFeO₃-PbZrO₃ for energy storage devices". Emerging Materials Research 12, nr 1 (1.03.2023): 1–8. http://dx.doi.org/10.1680/jemmr.21.00177.

Pełny tekst źródła

Streszczenie:

The solid-state reaction technique is used to prepare the samples 0.3(BiFeO3)–0.7(PbZrO3) and 0.5(BiFeO3)–0.5(PbZrO3). Structural parameters including percent crystallinity, dislocation density, microstrain, and the average size of crystallites are calculated using the X-Ray Diffraction (XRD) data at room temperature. The SEM micrographs reveal the spherical, densely packed natures of the samples with low porosity. Dielectric constant and dielectric loss increases with the rising content of Bismuth ferrite in the materials. The performance of the materials as an NTC thermistor in the temperature range 300–450°C is discussed. The values of the Thermistor constant (i.e. in the range of 3911–6247K) and the range of sensitivity index (−1 to −9%) confirmed the potential use of the samples as NTC thermistors. The frequency-dependent ac conductivity satisfies the universal Jonscher power law. The high density of states is determined from the frequency and temperature-dependent ac conductivity of the materials.

Style APA, Harvard, Vancouver, ISO itp.

35

Torres Sánchez, Rosa M., A. Boix i R. C. Mercader. "Grinding Assistance in the Transformation of Gibbsite to Corundum". Journal of Materials Research 17, nr 3 (marzec 2002): 712–17. http://dx.doi.org/10.1557/jmr.2002.0102.

Pełny tekst źródła

Streszczenie:

After gibbsite was milled for 5 min in a Cr-steel oscillating mill, corundum was obtained by heating the powder for 3 h at 800 °C. We found that iron contamination, produced by the milling process, is essential to attain the transformation at this low temperature and is located at the surface of the gibbsite particles. The knowledge of the oxidation state and location of the contaminant elements, necessary to control the solid-state reactions and/or phase transformations induced by the milling, was realized in this work by a characterization performed by chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and isoelectric point determination. The iron contamination amounted to about 3% (as Fe2O3) for the sample milled for 60 min. That the iron contamination that occurred mainly on the gibbsite amorphous surface was concluded after a comparison of the isoelectric point determination of the milled samples with that of a mechanical mixture of gibbsite and hematite. X-ray diffraction studies showed that gibbsite looses its crystallinity after the first 5 min of milling.

Style APA, Harvard, Vancouver, ISO itp.

36

Mohamed, Sara A., Mahrous R. Ahmed, H. M. Ali i A. M. Abdel Hakeem. "Structural, electrical and optical properties investigation of nano-sized Sb_0.1(SnO₂)_0.9". Physica Scripta 97, nr 4 (17.03.2022): 045810. http://dx.doi.org/10.1088/1402-4896/ac5bc4.

Pełny tekst źródła

Streszczenie:

Abstract Solid state reaction method was used to prepare Sbx(SnO2)1−x (x = 0 and 0.1) with sintering temperatures, 600 °C and 800 °C. The crystallographic properties of undoped and doped SnO2 materials results showed the tetragonal rutile structure of SnO2. The crystallinity was clear and increased with increasing the heat treatment. For the most diffraction peaks the microstrain is negative because do ˂ ds indicating the generation of residual compressive stress in the surface. Rietveld refinement proved that a good fitting parameters Rp, Rwp, and χ 2 makes the derived samples to be in a high quality, especially Sb0.1(SnO2)0.9 sample. Scanning Electron Microscopy (SEM) indicated that a spherical shape of SnO2 with nanoparticles but plates and nanorods shaped of SnO2 were detected for Sb0.1(SnO2)0.9 compound that was sintered at 800 °C. SnO2 has grain size 67 nm and 86 nm at sintering temperatures 600 °C and 800 °C respectively, but after adding Sb the grain size decreases to be ≈44 nm at the same sintering temperatures. The electrical resistivity, ρ, of Sb0.1(SnO2)0.9 behaved as semiconductor-like. The magnetoresistance, MR, results showed that ρ(0.6 tesla) < ρ(0 tesla) at Tsint = 600 °C where ρ (0.6 tesla) > ρ (0 tesla) at Tsint = 800 °C because the crystallinity increased with increasing of the sintering temperatures. The results of seebeck showed that charge carriers are n-tape at Tsint = 600 °C and p-type at Tsint = 800 °C. The optical energy band, E g of Sb0.1(SnO2)0.9 which were 2.49 eV and 3.21 eV at Tsint = 600 °C and 800 °C respectively and the high values of the transmittance make this compound is candidate to work as window layer in solar cell applications. The results of susceptibility denotes that the Sb0.1(SnO2)0.9 compound is a paramagnetic material.

Style APA, Harvard, Vancouver, ISO itp.

37

La Monaca, Andrea, Gabriel Girard, Sylvio Savoie, Giovanni Bertoni, Sergey Krachkovskiy, Ashok Vijh, Filippo Pierini, Federico Rosei i Andrea Paolella. "Synthesis of Electrospun NASICON Li_1.5Al_0.5Ge_1.5(PO₄)₃ Solid Electrolyte Nanofibers by Control of Germanium Hydrolysis". Journal of The Electrochemical Society 168, nr 11 (1.11.2021): 110512. http://dx.doi.org/10.1149/1945-7111/ac334a.

Pełny tekst źródła

Streszczenie:

We report the synthesis of ceramic Li1.5Al0.5Ge1.5(PO4)3 (LAGP) nanofibers by combining sol–gel and electrospinning techniques. A homogeneous and stable precursor solution based on chlorides was achieved by controlling Ge hydrolysis. Subsequent electrospinning and heat treatment resulted in highly porous nanostructured NASICON pellets. After a full chemical-physical characterization, various amounts of LAGP nanofibers were used as a filler to develop polyethylene oxide (PEO)-based composite electrolytes. The addition of 10% LAGP nanofibers has allowed doubling the ionic conductivity of the plain polymer electrolyte, by providing longer ion-conductive paths and reducing PEO crystallinity. These findings are promising towards developing solution-based synthesis approaches featuring Ge precursors. In addition, the achieved LAGP nanofibers proved to be a promising nanofiller candidate to develop composite electrolytes for next-generation solid-state batteries.

Style APA, Harvard, Vancouver, ISO itp.

38

Penilla, Elias H., Pathikumar Sellappan, Matthew A. Duarte, Andrew T. Wieg, Matthew C. Wingert i Javier E. Garay. "Bulk polycrystalline ceria–doped Al2O3 and YAG ceramics for high-power density laser-driven solid-state white lighting: Effects of crystallinity and extreme temperatures". Journal of Materials Research 35, nr 8 (7.02.2020): 958–71. http://dx.doi.org/10.1557/jmr.2019.417.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

39

Sim, San, Injun Hwang, Woosun Choi i Yongseon Kim. "Synthesis and Surface Coating of LiMn2O4 Nanorods for the Cathode of the Lithium-Ion Battery". Journal of Nanoscience and Nanotechnology 21, nr 10 (1.10.2021): 5289–95. http://dx.doi.org/10.1166/jnn.2021.19364.

Pełny tekst źródła

Streszczenie:

MnO2 nanorods are prepared using a hydrothermal method, and used as precursors for the synthesis of LiMn2O4 nanorod-based active material for the cathode of lithium-ion batteries. The effects of additives, pressure, reactant concentration in the solution, and reaction time during the hydrothermal synthesis on the morphology of MnO2 are examined. For the synthesis of the LiMn2O4 nanorods, two synthetic methods, hydrothermal processing of the MnO2 precursor in a Li-containing solution, and the solid-state reaction of the precursor with LiOH·H2O powder are tested. The morphological and electrochemical properties of the resulting materials are then analyzed. The rate and cycle performances of the LiMn2O4 nanorods are considerably improved by a composite coating of Li-ion-conductive Li2O–2B2O3 and electrically conductive carbon. Because the conductive properties of these coating materials can be obtained with low crystallinity of them, superior coating performance is attainable with relatively low-temperature of after heating, which is advantageous in preserving the morphology of LiMn2O4 nanorods.

Style APA, Harvard, Vancouver, ISO itp.

40

Que, Wenxiu, Siakpiang Lim, Xi Yao i A. Q. Liu. "A study on magnesium diffusion into LiNbO3 single crystal by x-ray diffraction, differential thermal analysis, and scanning electron microscopy". Journal of Materials Research 12, nr 12 (grudzień 1997): 3380–85. http://dx.doi.org/10.1557/jmr.1997.0444.

Pełny tekst źródła

Streszczenie:

The diffusion of magnesium into lithium niobate single crystal under different diffusion conditions has been studied by x-ray diffraction, glancing-incidence x-ray diffraction, differential thermal analysis, and scanning electron microscopy in an attempt to determine the diffusion mechanism and evaluate the crystallinity of the diffused layer. It is found that the magnesium diffused layer exhibits the crystal structure of an unknown compound from the Mg–Li–Nb–O ternary system and MgNb2O6. The MgNb2O6 is in the surface layer of the magnesium diffused layer, while the unknown compound is in the subsurface layer beneath the MgNb2O6. It is proposed that this unknown compound and MgNb2O6 which form during a solid state reaction between a thin layer of MgO and a lithium niobate crystal in a Li2O-rich atmosphere are the real sources for Mg ion indiffusion into lithium niobate crystal. The changes in Curie temperature with diffusion parameters are noted. Reasons of lattice distortion and mechanisms of Mg ion indiffusion are discussed and analyzed.

Style APA, Harvard, Vancouver, ISO itp.

41

Sabarinathan, V., C. Vinod Chandran, S. Ramasamy i S. Ganapathy. "119Sn Magic Angle Spinning NMR of Nanocrystalline SnO2". Journal of Nanoscience and Nanotechnology 8, nr 1 (1.01.2008): 321–28. http://dx.doi.org/10.1166/jnn.2008.18134.

Pełny tekst źródła

Streszczenie:

Nanocrystalline SnO2 samples of different grain sizes, prepared by inert gas condensation technique (IGCT) and chemical precipitation method and conforming to the tetragonal phase, have been studied by variable speed (3–10 kHz) 119Sn MAS NMR at 11.74 Tesla field. 119Sn solid-state NMR results show that the IGCT prepared samples have good crystallinity and phase purity compared to the samples prepared by the chemical method. The determination of 119Sn chemical shielding parameters (δiso, Δδ and η) from slow MAS spectra shows that the 119Sn isotropic chemical shift (δiso) is strongly influenced at smaller grain sizes, attributable to the change in the O2− local symmetry for the surface 119Sn ions at smaller grain sizes. The observed line widths in MAS spectra are significantly larger than the life-time broadening due to spin–lattice (T1) and spin–spin (T2) relaxation. The 119Sn MAS NMR spectra are thus inhomogeneously broadened by a distribution of isotropic chemical shifts, the line broadening increasing with decrease in grain size.

Style APA, Harvard, Vancouver, ISO itp.

42

Park, B. J., W. B. Im, W. J. Chung, H. S. Seo, J. T. Ahn i D. Y. Jeon. "Internal pressure effect on cathodoluminescence enhancement of ZnS:Mn2+ synthesized by a sealed vessel". Journal of Materials Research 22, nr 10 (październik 2007): 2838–44. http://dx.doi.org/10.1557/jmr.2007.0354.

Pełny tekst źródła

Streszczenie:

ZnS:Mn2+ phosphors were synthesized by a modified solid-state reaction method. In the synthesis method, a sealed vessel is used, where heat and pressure are simultaneously utilized. The effects of various synthesis conditions such as temperature, Mn concentration, and pressure on the cathodoluminescence (CL) were investigated. Among them, pressure had an effect on CL property as much as others. It was observed that CL intensities of ZnS:Mn2+ phosphors increased with the increase of pressure and the best sample showed higher intensity than that of a commercial one by 180%. X-ray diffraction (XRD) and electron paramagnetic-resonance (EPR) were used to understand the enhancement. No change of XRD patterns was observed but the full width at half-maximum (FWHM) of the most intense cubic (111) peak of ZnS:Mn2+ decreased with the increase of pressure. EPR signal intensity of Mn2+ increased with the increase of pressure. The improved crystallinity and more substitution of Zn2+ with Mn metal were believed to be responsible for the enhancement.

Style APA, Harvard, Vancouver, ISO itp.

43

Penilla, Elias H., Pathikumar Sellappan, Matthew A. Duarte, Andrew T. Wieg, Matthew Wingert i Javier E. Garay. "Bulk polycrystalline ceria–doped Al2O3 and YAG ceramics for high-power density laser-driven solid-state white lighting: Effects of crystallinity and extreme temperatures - CORRIGENDUM". Journal of Materials Research 35, nr 8 (17.03.2020): 1121–22. http://dx.doi.org/10.1557/jmr.2020.49.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

44

Isomura, Noritake, Keiichiro Oh-ishi, Naoko Takahashi i Satoru Kosaka. "Nanometer-scale depth-resolved hard x-ray absorption spectroscopy based on the detection of energy-loss Auger electrons with low energies". Journal of Vacuum Science & Technology A 40, nr 6 (grudzień 2022): 063204. http://dx.doi.org/10.1116/6.0002131.

Pełny tekst źródła

Streszczenie:

X-ray absorption spectroscopy (XAS) provides information on the chemical state and atomic structure of a target element even without long-range periodicity. A depth-resolved surface-sensitive XAS method for K-edge using hard x rays is proposed herein. The principle of this method is based on the selective detection of low-energy electrons using an electron analyzer. The detected electrons originate from the LMM Auger electrons that cascade from the KLL Auger process caused by K-shell absorption and lose the energy corresponding to their travel distance in a solid. The analysis depth was confirmed to be in the nanometer range using a GaN substrate with a thin oxide film of the defined thickness. In addition, depth-resolved information regarding the local atomic structure, including the interatomic distance and crystallinity, was obtained via the Fourier transformation of the spectral oscillations. Because the proposed technique does not require a change in the detection angle, it is also expected to be used for particles and samples with uneven surfaces.

Style APA, Harvard, Vancouver, ISO itp.

45

Xie, Jing, Gyeong-Hyeon Gwak, Minseop Lee, Seung-Min Paek i Jae-Min Oh. "Synthesis and Structural Analysis of Ternary Ca–Al–Fe Layered Double Hydroxides with Different Iron Contents". Crystals 11, nr 11 (26.10.2021): 1296. http://dx.doi.org/10.3390/cryst11111296.

Pełny tekst źródła

Streszczenie:

Hydrocalumite structured layered double hydroxides (LDHs) with various Fe3+ ratios were prepared through a coprecipitation method. In order to control the Fe3+ content in LDH, binary Ca–Fe LDHs were first synthesized with various Ca/Fe ratios. The X-ray diffraction pattern showed that only a limited Ca/Fe ratio resulted in LDH formation. The Fe3+ content in LDH was controlled by applying Al3+ while the divalent and trivalent metal ratio was set to 2. Through X-ray diffraction patterns, ternary LDHs with Ca–Al–Fe composition were successfully synthesized without significant impurities, with the Al increasing crystallinity. Quantification showed that Al moiety participated in the formation of the LDH framework more than Ca and Fe, implying a structural stabilization in the presence of Al. In order to investigate the global and local structure of Fe moiety in the LDH, both solid state UV-vis and X-ray absorption spectroscopies were carried out. Both spectroscopies revealed that the existence of Al induced slight local distortion in coordination but global crystal stabilization.

Style APA, Harvard, Vancouver, ISO itp.

46

Luo, Xiaobing, Jun Shen, He Huang, Lu Xu, Zhixiang Wang, Yang Chen i Li Li. "Near-Infrared Quantum Cutting in Yb3+ Doped SrMoO4 Phosphors". Journal of Nanoscience and Nanotechnology 16, nr 4 (1.04.2016): 3494–99. http://dx.doi.org/10.1166/jnn.2016.11801.

Pełny tekst źródła

Streszczenie:

Efficient near-infrared (NIR) quantum cutting (QC) has been demonstrated in Yb3+ doped SrMoO4 phosphors synthesized by the high-temperature solid-state reaction method. The obtained SrMoO4:Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra and decay lifetime to understand the observed near-infrared quantum cutting phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of SrMoO4 and exhibit good crystallinity. The experimental results showed that the strong visible molybdate (MoO2−24 emission around 493 nm and near-infrared (NIR) emission around 1000 nm from Yb3+(2F5/2 → 2F7/2) of SrMoO4:Yb3+ phosphors were observed under ultraviolet (290 nm) excitation. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches as high as 10 mol%. The cooperative energy transfer (CET) mechanism was also discussed in detail. The broadband NIR QC phosphors may possibly have potential application in enhancing the conversion efficiency of solar cells.

Style APA, Harvard, Vancouver, ISO itp.

47

Yen, Ching-Chi, Yu-Kai Liang, Chao-Pei Cheng, Mei-Chich Hsu i Yu-Tse Wu. "Oral Bioavailability Enhancement and Anti-Fatigue Assessment of the Andrographolide Loaded Solid Dispersion". International Journal of Molecular Sciences 21, nr 7 (4.04.2020): 2506. http://dx.doi.org/10.3390/ijms21072506.

Pełny tekst źródła

Streszczenie:

Andrographolide (AG), a major diterpene lactone isolated from Andrographis paniculata (Burm. f.) Nees (Acanthaceae), possesses a wide spectrum of biological activities. However, its poor water solubility and low bioavailability limit its clinical application. Therefore, this study aimed to develop a solid dispersion (SD) formulation to increase the aqueous solubility and dissolution rate of AG. Different drug-polymer ratios were used to prepare various SDs. The optimized formulation was characterized for differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffraction. The analysis indicated that the optimized SD enhanced AG solubility and dissolution rates by changing AG crystallinity to an amorphous state. The dissolution behaviors of the optimum SD composed of an AG-polyvinylpyrrolidone K30-Kolliphor EL ratio of 1:7:1 (w/w/w) resulted in the highest accumulated dissolution (approximately 80%). Pharmacokinetic studies revealed that Cmax/dose and the AUC/dose increased by 3.7-fold and 3.0-fold, respectively, compared with AG suspension. Furthermore, pretreatment using the optimized AG-SD significantly increased the swimming time to exhaustion by 1.7-fold and decreased the plasma ammonia level by 71.5%, compared with the vehicle group. In conclusion, the optimized AG-SD formulation appeared to effectively improve its dissolution rate and oral bioavailability. Moreover, the optimized AG-SD provides a promising treatment against physical fatigue.

Style APA, Harvard, Vancouver, ISO itp.

48

Markeev, Vladimir B., Evgenia V. Blynskaya, Sergey V. Tishkov, Konstantin V. Alekseev, Anna I. Marakhova, Alexandre A. Vetcher i Alexander Y. Shishonin. "Composites of N-butyl-N-methyl-1-phenylpyrrolo[1,2-a]pyrazine-3-carboxamide with Polymers: Effect of Crystallinity on Solubility and Stability". International Journal of Molecular Sciences 24, nr 15 (30.07.2023): 12215. http://dx.doi.org/10.3390/ijms241512215.

Pełny tekst źródła

Streszczenie:

This work aimed to develop and characterize a water-soluble, high-release active pharmaceutical ingredient (API) composite based on the practically water-insoluble API N-butyl-N-methyl-1-phenylpyrrolo[1,2-a]pyrazine-3-carboxamide (GML-3), a substance with antidepressant and anxiolytic action. This allows to ensure the bioavailability of the medicinal product of combined action. Composites obtained by the method of creating amorphous solid dispersions, where polyvinylpyrrolidone (PVP) or Soluplus® was used as a polymer, were studied for crystallinity, stability and the release of API from the composite into purified water. The resulting differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD), and dissolution test data indicate that the resulting composites are amorphous at 1:15 API: polymer ratios for PVP and 1:5 for Soluplus®, which ensures the solubility of GML-3 in purified water and maintaining the supercritical state in solution.

Style APA, Harvard, Vancouver, ISO itp.

49

Neary, Marianne T., David G. Reid, Matthew J. Mason, Tomislav Friščić, Melinda J. Duer i Maggie Cusack. "Contrasts between organic participation in apatite biomineralization in brachiopod shell and vertebrate bone identified by nuclear magnetic resonance spectroscopy". Journal of The Royal Society Interface 8, nr 55 (7.07.2010): 282–88. http://dx.doi.org/10.1098/rsif.2010.0238.

Pełny tekst źródła

Streszczenie:

Unusually for invertebrates, linguliform brachiopods employ calcium phosphate mineral in hard tissue formation, in common with the evolutionarily distant vertebrates. Using solid-state nuclear magnetic resonance spectroscopy (SSNMR) and X-ray powder diffraction, we compare the organic constitution, crystallinity and organic matrix–mineral interface of phosphatic brachiopod shells with those of vertebrate bone. In particular, the organic–mineral interfaces crucial for the stability and properties of biomineral were probed with SSNMR rotational echo double resonance (REDOR). Lingula anatina and Discinisca tenuis shell materials yield strikingly dissimilar SSNMR spectra, arguing for quite different organic constitutions. However, their fluoroapatite-like mineral is highly crystalline, unlike the poorly ordered hydroxyapatite of bone. Neither shell material shows 13 C{ 31 P} REDOR effects, excluding strong physico-chemical interactions between mineral and organic matrix, unlike bone in which glycosaminoglycans and proteins are composited with mineral at sub-nanometre length scales. Differences between organic matrix of shell material from L. anatina and D. tenuis , and bone reflect evolutionary pressures from contrasting habitats and structural purposes. The absence of organic–mineral intermolecular associations in brachiopod shell argues that biomineralization follows different mechanistic pathways to bone; their details hold clues to the molecular structural evolution of phosphatic biominerals, and may provide insights into novel composite design.

Style APA, Harvard, Vancouver, ISO itp.

50

Wang, Anye, Jian Zhang, Shuai Ye, Xiaofei Ma, Baiyi Wu, Siyuan Wang, Feifei Wang, Tao Wang, Baitao Zhang i Zhitai Jia. "Optimized Growth and Laser Application of Yb:LuAG Single-Crystal Fibers by Micro-Pulling-Down Technique". Crystals 11, nr 2 (20.01.2021): 78. http://dx.doi.org/10.3390/cryst11020078.

Pełny tekst źródła

Streszczenie:

Single-crystal fibers (SCFs) have a great application potential in high-power lasers due to their excellent performance. In this work, high-quality and crack-free Yb3+:Lu3Al5O12 (Yb:LuAG) SCFs were successfully fabricated by the micro-pulling-down (μ-PD) technology. Based on the laser micrometer and the X-ray Laue diffraction results, these Yb:LuAG SCFs have a less than 5% diameter fluctuation and good crystallinity along the axial direction. More importantly, the distribution of Yb ions is proved to be uniform by electron probe microanalysis (EPMA) and the scanning electron microscope (SEM). In the laser experiment, the continuous-wave (CW) output power using a 1 mm diameter Yb:LuAG single-crystal fiber is determined to be 1.96 W, at the central wavelength of 1047 nm, corresponding to a slope efficiency of 13.55%. Meanwhile, by applying a 3 mm diameter Yb:LuAG SCF, we obtain a 4.7 W CW laser output at 1049 nm with the slope efficiency of 22.17%. The beam quality factor M2 is less than 1.1 in both conditions, indicating a good optical quality of the grown fiber. Our results show that the Yb:LuAG SCF is a potential solid-state laser gain medium for 1 μm high-power lasers.

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Solid State Physics - Crystallinity”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych