|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||High Entropy Alloys VIII
||High Entropy Alloys for Magnetocaloric Effect Applications
||Michael E. McHenry, Alice Elizabeth Perrin
|On-Site Speaker (Planned)
||Michael E. McHenry
Magnetocaloric effect (MCE) materials offer efficient, environmentally friendly refrigeration. Rare earths metal (REs) compounds have large MCE near room temperature but their scarcity, high price and corrosion limit their use. Transition metal based high entropy alloys (HEAs) exhibit convenient tunability of Curie temperatures, Tc’s, use of inexpensive components and tunability of magnetic phase transformation breadth by distributing pair-wise exchange interactions on an fcc crystalline lattice. Intermetallics with less critical rare earths exhibit 1st order magnetostructural phase transitions where HEA arguments inspire compositional modifications.
I will present Tc engineering in direct exchange coupled metals using the Bethe-Slater curve and Pauli exclusion principle constraints to explain composition- and pressure-dependence of Tc and Mossbauer spectra, where the average hyperfine field (and Tc) is proportional to the average pairwise exchange interaction. The P-dependence of Tc is interpreted for FeCoNiMnCu HEAs. Concepts for extending high entropy ideas to intermetallics in NaZn13-type cluster solids are presented.
||Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume