[SY-D5] Symposium D-5

[SY-D5] High-throughput optimization of finite temperature phase stabilities of Ce-based hard magnetic materials

^○Tilmann Hickel, Halil Soezen, Fritz Koermann, Joerg Neugebauer (Max Planck Institut fur Eisenforschung, Germany)

While the present search for novel materials concepts to improve hard magnetic applications is concentrated on the magnetic properties of individual phases, their finite temperature phase stabilities are largely unknown. In the Ce-Fe-Ti ternary system, for example, the promising phase CeFe₁₁Ti is competing with various Laves phases as demonstrated by energy-dispersive X-ray spectroscopy (EDS) measurements. We therefore use concepts of ab initio thermodynamics capturing vibrational, electronic and magnetic entropy contributions in order to determine the Helmholtz free energy of all relevant phases. Several additional elements have been considered within this formalism, to investigate their partitioning and impact on the relative phase stabilities. The insights obtained demonstrate how the screening of a complete set of transition metals in quarternary hard magnetic materials can be performed most efficiently and which alloying elements improve the stability of promising phases such as CeFe₁₁Ti most substantially.