Structural interpretation of the Prigogine-Defay ratio at the glass transition

Article

关键词: TEMPERATURE THERMAL-CONDUCTIVITY;    EHRENFEST RELATIONS;    BOSON PEAK;    THERMODYNAMICS;    LIQUID;    RELAXATION;    VIBRATIONS;   

DOI  :  10.1103/PhysRevB.86.184105

来源: SCIE

【 摘 要 】

On cooling through the glass transition, a many-particle system freezes into one of the many inherent structurally stable states which are freely accessible in the undercooled liquid. This implies a freezing of an additional heat capacity, an additional thermal expansion, and an additional compressibility. Analyzing the volume and energy distribution of the inherent states at the glass transition, one finds two kinds of slow density fluctuations, namely those which do require an energy change and those which do not. Their ratio determines the Prigogine-Defay ratio. If the second kind is absent, the Prigogine-Defay ratio is unity, enthalpy and volume fluctuations are strictly correlated, and the structural relaxation processes do not couple to an external compression. This case is not often found in real glasses, but seems to be realized to good approximation in Lennard-Jones systems, probably also in metallic glasses. In these two cases, the zero coupling is also reflected in the boson peak modes.

【 授权许可】

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