Magnetic transition behavior and electromagnetic properties of Zr substituted Bi0.5Y1.5−xCa1+xZrxV0.5Fe4.5−xO12 garnets

Zr substituted Bi_0.5Y_1.5−xCa_1+xZr_xV_0.5Fe_4.5−xO₁₂ (x = 0.00, 0.25, 0.50, 0.75, 1.00) samples were prepared via solid-state reaction method. The structure, morphology, electromagnetic properties of Zr-doped Bi_0.5Y_1.5−xCa_1+xZr_xV_0.5Fe_4.5−xO₁₂ were investigated by SEM, XRD, FT-IR, Raman, VSM, impedance analyzer, and vector network analyzer. The results showed that the Zr⁴⁺ and Ca²⁺ ions successfully entered the octahedral a-sites and dodecahedral c-sites, respectively. The saturation magnetization increased with the increase of doping concentration in low concentration range. However, the excessive dopant of diamagnetic Zr⁴⁺ ions resulted in a decrease in the saturation magnetization, indicating that the crystal lattice appeared short-range antiferromagnetic order at the d-sites, and the samples changed from ferromagnetism to paramagnetism. Among them, Bi_0.5Y_1.25Ca_1.25Zr_0.25V_0.5Fe_4.25O₁₂ has the optimum comprehensive properties, M_s = 17.254 emu/g, H_c = 4.043 Oe, M_r = 0.268 emu/g, ΔH = 81 Oe, ε_r = 18.68 @ 1 MHz, and tanδ_ε = 0.002. The as-prepared material has potential application in communication devices such as circulators and isolators.