Universal enthalpy-entropy compensation rule for the deformation of metallic glasses.

The thermodynamic compensation law describing an empirical linear relationship between activation enthalpy and activation entropy has seldom been validated for amorphous solids. Here molecular dynamics simulations reveal a well-defined enthalpy-entropy compensation rule in a metallic glass (MG) over a wide temperature and stress range, spanning the glass transition induced by temperature and/or stress. Experiments on other MGs reproduce this law, suggesting that it applies universally to amorphous solids, so we extend it from crystals to amorphous solids. In the glassy state, the compensation temperature is found to agree with the thermal glass transition temperature Tg; whereas in the supercooled liquid region, the compensation temperature matches ~ L4Tg, at which the diffusion kinetics start to feel the roughness of the free-energy surface. [ABSTRACT FROM AUTHOR]