Cationic disorder: Governing the spin-insulatronic properties of nanocrystalline ZnFe2O4 thin films

Controlling cation order/disorder in spinel offers a highly effective means of tailoring material properties by modifying inter- and intra-sub-lattice ionic interactions. In this study, we conducted high -temperature magnetization measurements (300-1000 K) to determine average Curie temperatures (TC) for nanocrystalline ZnFe2O4 thin films. Thermodynamical stability of these films under extreme conditions was investigated by assessing lattice structures, oxygen vacancies, magnetization, and electric resistivity for spin-insulatronic applications. Reversible cation inversion via heat treatments (in -situ and ex -situ) yields tunable ferrimagnetic (FiM) order in ZnFe2O4, with TC ranging from 425 to 710 K. First -principles calculations highlight effective cation inversion mitigating magnetic frustration, promoting collinear FiM ordering, and elevating TC. Oxygen vacancies further reinforce ferrimagnetism, slightly reducing resistivity through the formation of Fe -3d gap states near the Fermi level. A proposed magnetic nanophase diagram elucidates dominant competing magnetic ground states (cluster spin -glassy state, FiM, and antiferromagnetic) with increasing growth temperature, fostering innovative homoarchitectures from multiple ZnFe2O4 thin films with diverse functionalities.