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Title: High-precision measurements of the compressibility of chalcogenide glasses at a hydrostatic pressure up to 9 GPa

Abstract

The volumes of glassy germanium chalcogenides GeSe{sub 2}, GeS{sub 2}, Ge{sub 17}Se{sub 83}, and Ge{sub 8}Se{sub 92} are precisely measured at a hydrostatic pressure up to 8.5 GPa. The stoichiometric GeSe{sub 2} and GeS{sub 2} glasses exhibit elastic behavior in the pressure range up to 3 GPa, and their bulk modulus decreases at pressures higher than 2–2.5 GPa. At higher pressures, inelastic relaxation processes begin and their intensity is proportional to the logarithm of time. The relaxation rate for the GeSe{sub 2} glasses has a pronounced maximum at 3.5–4.5 GPa, which indicates the existence of several parallel structural transformation mechanisms. The nonstoichiometric glasses exhibit a diffuse transformation and inelastic behavior at pressures above 1–2 GPa. The maximum relaxation rate in these glasses is significantly lower than that in the stoichiometric GeSe{sub 2} glasses. All glasses are characterized by the “loss of memory” of history: after relaxation at a fixed pressure, the further increase in the pressure returns the volume to the compression curve obtained without a stop for relaxation. After pressure release, the residual densification in the stoichiometric glasses is about 7% and that in the Ge{sub 17}Se{sub 83} glasses is 1.5%. The volume of the Ge{sub 8}Se{sub 92} glassmore » returns to its initial value within the limits of experimental error. As the pressure decreases, the effective bulk moduli of the Ge{sub 17}Se{sub 83} and Ge{sub 8}Se{sub 92} glasses coincide with the moduli after isobaric relaxation at the stage of increasing pressure, and the bulk modulus of the stoichiometric GeSe{sub 2} glass upon decreasing pressure noticeably exceeds the bulk modulus after isobaric relaxation at the stage of increasing pressure. Along with the reported data, our results can be used to draw conclusions regarding the diffuse transformations in glassy germanium chalcogenides during compression.« less

Authors:
 [1];  [2];  [1]
  1. Vereshchagin Institute of High-Pressure Physics (Russian Federation)
  2. Universite du Littoral, LPCA, UMR 8101 CNRS (France)
Publication Date:
OSTI Identifier:
22617205
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 123; Journal Issue: 2; Other Information: Copyright (c) 2016 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACCURACY; CHALCOGENIDES; COMPRESSIBILITY; COMPRESSION; ERRORS; GERMANIUM COMPOUNDS; GERMANIUM SELENIDES; GERMANIUM SULFIDES; GLASS; HYDROSTATICS; PRESSURE RANGE GIGA PA; PRESSURE RELEASE; RELAXATION; STOICHIOMETRY

Citation Formats

Brazhkin, V. V., E-mail: brazhkin@hppi.troitsk.ru, Bychkov, E., and Tsiok, O. B.. High-precision measurements of the compressibility of chalcogenide glasses at a hydrostatic pressure up to 9 GPa. United States: N. p., 2016. Web. doi:10.1134/S1063776116060108.
Brazhkin, V. V., E-mail: brazhkin@hppi.troitsk.ru, Bychkov, E., & Tsiok, O. B.. High-precision measurements of the compressibility of chalcogenide glasses at a hydrostatic pressure up to 9 GPa. United States. doi:10.1134/S1063776116060108.
Brazhkin, V. V., E-mail: brazhkin@hppi.troitsk.ru, Bychkov, E., and Tsiok, O. B.. 2016. "High-precision measurements of the compressibility of chalcogenide glasses at a hydrostatic pressure up to 9 GPa". United States. doi:10.1134/S1063776116060108.
@article{osti_22617205,
title = {High-precision measurements of the compressibility of chalcogenide glasses at a hydrostatic pressure up to 9 GPa},
author = {Brazhkin, V. V., E-mail: brazhkin@hppi.troitsk.ru and Bychkov, E. and Tsiok, O. B.},
abstractNote = {The volumes of glassy germanium chalcogenides GeSe{sub 2}, GeS{sub 2}, Ge{sub 17}Se{sub 83}, and Ge{sub 8}Se{sub 92} are precisely measured at a hydrostatic pressure up to 8.5 GPa. The stoichiometric GeSe{sub 2} and GeS{sub 2} glasses exhibit elastic behavior in the pressure range up to 3 GPa, and their bulk modulus decreases at pressures higher than 2–2.5 GPa. At higher pressures, inelastic relaxation processes begin and their intensity is proportional to the logarithm of time. The relaxation rate for the GeSe{sub 2} glasses has a pronounced maximum at 3.5–4.5 GPa, which indicates the existence of several parallel structural transformation mechanisms. The nonstoichiometric glasses exhibit a diffuse transformation and inelastic behavior at pressures above 1–2 GPa. The maximum relaxation rate in these glasses is significantly lower than that in the stoichiometric GeSe{sub 2} glasses. All glasses are characterized by the “loss of memory” of history: after relaxation at a fixed pressure, the further increase in the pressure returns the volume to the compression curve obtained without a stop for relaxation. After pressure release, the residual densification in the stoichiometric glasses is about 7% and that in the Ge{sub 17}Se{sub 83} glasses is 1.5%. The volume of the Ge{sub 8}Se{sub 92} glass returns to its initial value within the limits of experimental error. As the pressure decreases, the effective bulk moduli of the Ge{sub 17}Se{sub 83} and Ge{sub 8}Se{sub 92} glasses coincide with the moduli after isobaric relaxation at the stage of increasing pressure, and the bulk modulus of the stoichiometric GeSe{sub 2} glass upon decreasing pressure noticeably exceeds the bulk modulus after isobaric relaxation at the stage of increasing pressure. Along with the reported data, our results can be used to draw conclusions regarding the diffuse transformations in glassy germanium chalcogenides during compression.},
doi = {10.1134/S1063776116060108},
journal = {Journal of Experimental and Theoretical Physics},
number = 2,
volume = 123,
place = {United States},
year = 2016,
month = 8
}
  • The authors have studied the crystallizability and determined the compositions of the phases separating out during crystallization of glasses based on the eutectic composition Sb/sub 19.2/Ge/sub 21.4/Se/sub 59.4/, which is located near the boundary of the region of glass formation in the Sb-Ge-Se system with a deficiency of selenium. X-ray diffraction studies were carried out. During crystallization of Sb/sub 19.2/Ge/sub 21.4/Se/sub 59.4/ glass with additions of tin, lead, and tellurium replacing their chemical analogs, the primary crystallization products may be Sb/sub 2/Se/sub 3/, GeSe/sub 2/, GeSe, GeTe, SnSe, PbSe, PbTe, Sb/sub 2/Te/sub 3/, some of which (cubic GeTe, rhombic PbSemore » and PbTe) were observed earlier only at high pressures or temperature (GeTe). The high-pressure structure pattern has an active influence on the symmetry of other crystalline phases.« less
  • High-pressure x-ray diffraction studies have been carried out on the two group IV transition metals-based bulk metallic glasses (BMGs) Zr{sub 57}Cu{sub 15.4}Ni{sub 12.6}Al{sub 10}Nb{sub 5} and Ti{sub 42}Zr{sub 24}Cu{sub 15.5}Ni{sub 14.5}Be{sub 4} to a pressure of 30 GPa at ambient temperature in a diamond anvil cell. Image plate x-ray diffraction studies under high pressure were carried out at a synchrotron source and the two BMG diffraction bands can be followed to the highest pressure using an internal copper pressure standard. The amorphous phase is observed to be stable to the highest static pressure of 30 GPa suggesting that the phasemore » change observed in dynamical pressure experiments is related to an increase in temperature. The measured bulk modulus (B{sub 0}) and its pressure derivative (B') are 118 GPa and 3.11 for Zr-based BMG and 116 GPa and 2.84 for Ti-based BMG. The measured bulk modulus for BMG's by x-ray diffraction technique is consistent with the ultrasonic measurements. The decompression data reveal an increase in density by 3%-4% at ambient condition after pressure cycling to 30 GPa indicating reduction in excess free volume.« less
  • We report compressibility measurements for three transition metal nitrides ({epsilon}-TaN, {delta}-MoN, Cr{sub 2}N) that have structures based on hexagonal arrangements of the metal atoms. The studies were performed using monochromatic synchrotron x-ray diffraction at high pressure in a diamond anvil cell. The three nitride compounds are well-known high hardness materials, and they are found to be highly incompressible. The bulk modulus values measured for {epsilon}-TaN, Cr{sub 2}N, and {delta}-MoN are K{sub 0}=288(6) GPa, 275(23) GPa, and 345(9) GPa, respectively. The data were analyzed using a linearized plot of reduced pressure (F) vs the Eulerian finite strain variable f within amore » third-order Birch-Murnaghan equation of state formulation. The K{sub 0}{sup '} values for {epsilon}-TaN and {delta}-MoN were 4.7(0.5) and 3.5(0.3), respectively, close to the value of K{sub 0}{sup '}=4 that is typically assumed in fitting compressibility data in equation of state studies using a Birch-Murnaghan equation. However, Cr{sub 2}N was determined to have a much smaller value, K{sub 0}{sup '}=2.0(2.0), indicating a significantly smaller degree of structural stiffening with increased pressure. We also present Raman data for {epsilon}-TaN and {delta}-MoN at high pressure in order to characterize the phonon behavior in these materials. All of the Raman active modes for {epsilon}-TaN were identified using polarized spectroscopy. Peaks at low frequency are due to Ta motions, whereas modes at higher wave number contain a large component of N motion. The high frequency modes associated with Ta-N stretching vibrations are more sensitive to compression than the metal displacements occurring at lower wave number. The mode assignments can be generally extended to {delta}-MoN, that has a much more complex Raman spectrum. The x-ray and Raman data for {epsilon}-TaN show evidence for structural disordering occurring above 20 GPa, whereas no such change is observed for {delta}-MoN.« less
  • The local structure of crystalline and glassy compositions in the (Li{sub 2}S){sub x}(P{sub 2}S{sub 5}){sub 1{minus}x} system is investigated by solid-state high-resolution {sup 31}P, {sup 6}Li, and {sup 7}Li MAS NMR. Four stable crystalline pseudobinary compounds, LiPS{sub 3}, Li{sub 4}P{sub 2}S{sub 6}, Li{sub 3}PS{sub 4}, and Li{sub 7}PS{sub 6}, are identified. The NMR results illustrate the role of the glassy state in trapping metastable local environments that have no analogues in crystalline compounds.