Ames Laboratory; Materials Science and Engineering; Chemical and Biological Engineering; Physics and Astronomy
Ames Laboratory, Materials Science and Engineering, Chemical and Biological Engineering, Physics and Astronomy
Journal of Alloys and Compounds
Reversible, diffusionless, first-order solid-solid phase transitions accompanied by caloric effects are critical for applications in the solid-state cooling and heat-pumping devices. Accelerated discovery of caloric materials requires reliable but faster estimators for predictions and high-throughput screening of system-specific dominant caloric contributions. We assess reliability of the computational methods that provide thermodynamic properties in relevant solid phases at or near a phase transition. We test the methods using the well-studied B2 FeRh alloy as a “fruit fly” in such a materials genome discovery, as it exhibits a metamagnetic transition which generates multicaloric (magneto-, elasto-, and baro-caloric) responses. For lattice entropy contributions, we find that the commonly-used linear-response and small-displacement phonon methods are invalid near instabilities that arise from the anharmonicity of atomic potentials, and we offer a more reliable and precise method for calculating lattice entropy at a fixed temperature. Then, we apply a set of reliable methods and estimators to the metamagnetic transition in FeRh (predicted 346 ± 12 K, observed 353 ±1 K) and calculate the associated caloric properties, such as isothermal entropy and isentropic temperature changes.
DOE Contract Number(s)
Department of Energy Subject Categories
36 MATERIALS SCIENCE
Iowa State University Digital Repository, Ames IA (United States)