Observation of a pressure-induced first-order polyamorphic transition in a chalcogenide glass at ambient temperature.
An apparently first-order polyamorphic transition has been observed with increasing pressure at ambient temperature in a molecular glass of composition Ge(2.5)As(51.25)S(46.25) Raman spectroscopic measurements on pressure-quenched samples and in situ x-ray diffraction measurements indicate that this transition corresponds to a collapse of the ambient-pressure molecular phase to a high-pressure network phase. The high-pressure phase first appears at a pressure of approximately 8-9 GPa and the transformation becomes complete at approximately 14-15 GPa. Calorimetric measurements indicate that the low- and high-pressure phases are thermodynamically distinct and that they coexist in the transition range.
Sen
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Department of Chemical Engineering and Materials Science, University of California, Davis, 95616, USA.
Gaudio
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Aitken
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Lesher
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