Structural and Magnetic Properties of Sr_3-xLa_xCo₂Fe₂₄O₄₁ Hexaferrite

In the present work, La³⁺ ion substituted strontium Z-type hexaferrites (Sr_3-xLa_xCo₂Fe₂₄O₄₁ (x = 0, 0.05, 0.10, 0.15, 0.20, and 0.25)) have been synthesized using solid-state reaction method. The effect of substitution on its structural and magnetic properties was investigated. X-ray diffraction (XRD) pattern confirms the formation of single-phase Z-type hexaferrite. The XPS spectra provide the evidence for formation of Fe²⁺ in La-substituted SrZ hexaferrites. FESEM micrographs of as prepared samples showed a reduction in grain size with the increasing La substitution. The behavior of substitution at various crystallographic sites was analyzed by Raman spectroscopy. The increase in saturation magnetization (M_s) and coercivity (H_c) was observed with increasing La content from x = 0 to x = 0.25.