Pressure-Driven Chemical Disorder in Glassy As2S3 up to 14.7 GPa, Postdensification Effects, and Applications in Materials Design
Autor: | Eugene Bychkov, Oleg B Tsiok, Anton Sokolov, Andrey Tverjanovich, Emmanuel Soignard, A. Bytchkov, Vadim V. Brazhkin, Chris J. Benmore |
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Rok vydání: | 2019 |
Předmět: |
Diffraction
education.field_of_study Materials science 010304 chemical physics Population 010402 general chemistry 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Chalcogen Chemical physics 0103 physical sciences Materials Chemistry Compressibility Relaxation (physics) Physical and Theoretical Chemistry Absorption (chemistry) education Refractive index Saturation (magnetic) |
Zdroj: | The Journal of Physical Chemistry B. 124:430-442 |
ISSN: | 1520-5207 1520-6106 |
Popis: | A small difference in energy between homopolar and heteropolar bonds and the glass-forming ability of pure chalcogens leads to unexpected trends in densification mechanisms of glassy chalcogenides compared to vitreous oxides. Using high-precision compressibility measurements and in situ high-energy X-ray diffraction up to 14.7 GPa, we show a new densification route in a canonical glass As2S3. After the first reversible elastic step with a maximum pressure of 1.3 GPa, characterized by a strong reduction of voids and cavities, a significant bonding or chemical disorder is developed under higher pressure, reaching a saturation of 30% in the population of As-As bonds above 8-9 GPa. The pressure-driven chemical disorder is accompanied by a remarkable structural relaxation and a strongly diminished optical gap and determines structural, vibrational, and optical properties under and after cold compression. The decompressed recovered glass conserves a dark color and exhibits two relaxation processes: (a) fast (a few days) and (b) slow (months/years at room temperature). The enhanced refractive index of the recovered glass is promising for optical applications with improved functionalities. A nearly permanent red shift in optical absorption after decompression can be used in high-impact-force optical sensors. |
Databáze: | OpenAIRE |
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