International Journal Thermophysics

A researcher at The University of Osaka has proposed a thermodynamic framework for describing hysteresis in solids, a history-dependent phenomenon widely used in memory devices, energy conversion materials, and other technologies. The study shows that hysteresis can, in principle, be described within thermodynamics when the state of a solid is defined not only by conventional variables such as temperature and volume, but also by its atomic configuration. By identifying the time-averaged equilibrium positions of atoms as essential state variables, the work provides a more rigorous theoretical foundation for understanding and developing solid-state materials that rely on hysteresis.