Realizing Antiferromagnetic-Ferromagnetic Transition and Giant Enhancement of Magnetism in Co(Ga2-xFex)O4 Spinel Ferrites

Abstract

The modulation of ions substitution has been regarded as a promising route to induce magnetic transition and tailor intrinsic properties for spinel ferrites as expected. Herein, Fe-substituted Co(Ga_2-xFe_x)O₄ spinel ferrites have been successfully prepared by a solid-state method. It is shown that the lattice constant increases gradually with the rising amount of Fe substitution due to a larger ionic radius of Fe than that of Ga. More importantly, a significant improvement in magnetic properties has been achieved under the effort of Fe substitution, especially in intrinsic coercivity (H_c). Correspondingly, the saturation magnetization (M_s), H_c, and Curie temperature (T_C) increase from 11.01 emu/g, 0.29 kOe, and 10 K to 86.05 emu/g, 11.45 kOe, and 318 K respectively based on Fe substitution. Our work realizes a marked modulation of magnetic properties in Co(Ga_2-xFe_x)O₄, providing a fundamental strategy for magnetism tuning as well as the development of magnetic devices.