Influence of samarium substitution on microwave magnetic performance of Mn-Zn ferrite

The Mn-Zn ferrite doped with Sm³⁺, Mn_0.3Zn_0.7 Fe_2-xSm_xO₄(x=0, 0.01, 0.02, 0.04,0.06), were prepared by the conventional ceramic technology. The structure and electromagnetic properties of the calcined samples were studied using powder X-ray diffraction (XRD) and network analyzer (Agilent 8722ET). When x was below 0.02, the XRD patterns showed the relatively pure phase of the spinel ferrite. The lattice parameters of ferrites first increased and then decreased with substitution amount. The micro-wave electromagnetic properties of the samples were studied at the frequency range from 2 to 18 GHz. It was shown that ε′ and ε″ increased slightly at the frequency range from 9 GHz to 18 GHz, and the maximum of ε″ appeared at low frequency position when x = 0.02. The maxima of μ″ and μ″ were improved significantly, and the maxima were 6.2 and 5.5, respectively. It was indicated that the microwave electromagnetic properties were excellent when x = 0.02. All the reasons were also discussed using electromagnetic theory.