Effects of In-substitution on the microstructure and magnetic properties of Bi-CVG ferrite with low temperature sintering

摘要

[Y_(1.05)Bi_(0.75)Ca_(1.2)](Fe_(4.4-x)In_xV_(0.6))O_(12)(In_x:Bi-CVG) ferrite material has been prepared successfully by a solid-state reaction method. The effects of In~(3+) substitution and sintering temperatures on the bulk density, microstructure and magnetic properties are performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), materials automatic test system (MATS) and microwave ferrite parameters meter. The results show that In~(3+) can lower the sintering temperatures and enhance the magnetic properties of Bi-CVG ferrite. Besides, all sintered specimens with different In~(3+) contents show a single garnet crystal structure. The specimen of [Y_(1.05)Bi_(0.75)Ca_(1.2)](Fe_4In_(0.4)V_(0.6)O_(12) sintered at 1075 ℃ shows homogenous distribution of grain size and densified microstructures. The ferromagnetic resonance linewidth (△H) has an increase with In~(3+) contents. Additionally, the sample has the optimum magnetic properties: p = 5.23 g/cm~3, B_r=31.3 mT, H_c=378.8 A/m, 4πM_s=506.2 × 10~(-4)T.