The nano-crystalline rare earth (Sm³⁺, Dy³⁺) substituted MgFe₂O₄ with composition Mg[(Sm)_0.6(Dy)_0.4]_xFe_2-xO₄ [x varies from 0.0 to 0.3 in steps of 0.05] have been prepared by chemical combustion route. X-ray diffraction analysis confirmed the formation of the spinel cubic phase as a major phase along with the perovskite ortho-ferrite phase as a minor phase in all the samples except MgFe₂O₄. The room temperature magnetic properties of these samples have been investigated. It has been observed that with an increase in substitution of rare-earth ions (Sm³⁺, Dy³⁺), for iron in MgFe₂O₄, initial permeability increases, attain peak value for the composition with x = 0.15, and decreases for higher substitution concentrations. The microwave absorption performance of the Mg[(Sm)_0.6(Dy)_0.4]_xFe_2-xO₄ systems have been investigated. The reflection coefficients are found to be higher as compared to MgFe₂O₄ whereas Voltage Standing Wave Ratio (VSWR) found to be lower. Overall investigations indicate Mg[(Sm)_0.6(Dy)_0.4]_0.15Fe_1.85O₄ is a promising candidate for microwave device fabrication.

纳米晶稀土 (Sm ³⁺ , Dy ³⁺ ) 取代 MgFe ₂ O ₄，其组成为 Mg[(Sm) _0.6 (Dy) _0.4 ] _x Fe _2-x O ₄ [x 从 0.0 变化到 0.3，步长为0.05]已通过化学燃烧途径制备。X 射线衍射分析证实，在除 MgFe ₂ O ₄之外的所有样品中，形成了作为主要相的尖晶石立方相以及作为次要相的钙钛矿正铁素体相。已经研究了这些样品的室温磁性能。据观察，随着稀土离子（Sm³⁺ , Dy ³⁺ )，对于 MgFe ₂ O _{4 中的}铁，初始磁导率增加，在 x = 0.15 的成分中达到峰值，并且随着置换浓度的升高而降低。已经研究了Mg[(Sm) _0.6 (Dy) _0.4 ] _x Fe _2-x O ₄系统的微波吸收性能。与MgFe ₂ O ₄相比，发现反射系数更高，而发现电压驻波比(VSWR)更低。总体调查表明 Mg[(Sm) _0.6 (Dy) _0.4 ] _0.15 Fe _1.85O ₄是微波器件制造的有前途的候选者。