Magnetic and microwave absorption properties of Cu/Zr doped M-type Ba/Sr hexaferrites prepared via sol-gel auto-combustion method

In this research, the magnetic, structural and microwave properties of Ba_0.5Sr_0.5Cu_XZr_XFe_12-2xO₁₉ (BSCZH) (where x = 0–0.8) hexaferrite nanoparticle prepared by the auto-combustion sol-gel method have been investigated. The effect of substituted Cu⁺²-Zr⁺⁴ ions of the barium strontium hexaferrite was characterized by FT-IR, XRD, SEM, VSM and VNA methods. The XRD pattern represents that the materials have a single magnetoplumbite phase, and the crystalline size of the particles varies from 42 to 48 nm at X = 0–0.8%. The coercivity (H_c) and saturation magnetization (M_s) and remanent magnetization (M_r) obtained by VSM (Vibrating Sample Magnetometer) technique. The results of the magnetic measurement indicate that the coercivity decreases by substitution of Cu⁺²-Zr⁺⁴ from x = 0 (5010 Oe) to x = 0.8(301.18 Oe) whereas saturation magnetization (M_s) first increased from x = 0–0.4 mol% and then decreased from x = 0.6 to 0.8. FESEM results indicate that the particle morphology is randomly hexagonal. Also, microwave properties of Ba_0.5Sr_0.5Cu_0.4Zr_0.4Fe_11.2O₁₉ (BSCZH) exhibit the minimum reflection loss of −15.2 db at 11.1 GHz and the result shows that Cu⁺²-Zr⁺⁴ substation on the barium strontium hexaferrite nanoparticle is useful for microwave application in the frequency range 8–12 GHz.