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

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- x Fe x )O 4 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- x Fe x )O 4 , providing a fundamental strategy for magnetism tuning as well as the development of magnetic devices.