Landau-Khalatnikov theory of anelastic relaxations in spin-crossover materials

Le résumé fourni par la source

Large anelastic relaxations have been found near the transition temperature in spin crossover (SCO) materials due to stress-induced changes in spin state. To investigate the mechanistic aspects of this phenomenon, we develop here a phenomenological framework, based on the Landau theory of phase transitions, incorporating coupling terms between spin state and elastic strain, which is also extended to the dynamic Landau-Khalatnikov regime. We derive an analytical solution for the mechanical response and conduct a parametric study of a cubic SCO system. Our simulations reveal bulk modulus relaxation, internal friction peaks and renormalization of elastic constants near the spin transition - qualitatively matching recent nanoindentation experiments. The work clarifies the roles of bilinear and higher-order couplings in shaping static and dynamic elastic anomalies, with relevance for mechanical actuator design.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.