Correlation between entropy state, crystal structure, magnetic and electrical properties in M-type Ba-hexaferrites

Abstract Low-entropy (un-substituted Ba-hexaferrite) and High-entropy (polysubstituted Ba-hexaferrite with Ga/In/Ti/Cr/Co ions) samples were synthesized. The crystal structure, microstructure, magnetic and electrical properties of BaFe12O19 and Ba(Fe6.00Ga1.26In1.17Ti1.20Cr1.22Co1.15)O19 ceramic samples were investigated. It was established that there is a correlation between entropy state and the features of crystal structure. Magnetic properties are critically depended on entropy state and intensity of super exchange interactions. Magnetic phase separation was observed (coexistence of the classical multi domain states and magnetic “nano regions”) in HE-samples. In hexaferrites, a strong coupling between entropy state, magnetic and electrical properties was demonstrated.