Effect of ZrO2 addition on the microstructure and electromagnetic properties of YIG

In this work, we reported the microstructure and electromagnetic properties of a series of zirconium substituted yttrium iron garnet ferrites (YCaZrIG) with iron deficiency composition of Y3−xCaxZrxFe4.93−xO12 (x = 0.1, 0.2, 0.3, and 0.4, with electrostatic balance by Ca2+ substituted for Y3+ ions) prepared by a solid-reaction method. The addition of ZrO2 shows no obvious influence on the phase, density and dielectric constant of YIG ferrites. When Zr addition x ≤ 0.3, the substitution of Zr4+ for Fe3+ decreases the amount of Fe ions, increases the lattice parameter and enhances the grain growth of garnet phase. The solubility of zirconium in YCaZrIG ferrite was found to be approximately 0.3, above which excess ZrO2 would lead to the precipitation of a second phase inside the YCaZrIG ferrite. This would inhibit the grain growth of garnet phase and cause an increase in the dielectric loss and coercivity. The observed reduce for saturation magnetization when x = 0.4 is possibly due to antiparallel alignment of magnetic moment of Fe3+ in the d site caused by the decrease of a–d exchange interaction. Additionally, we got the optimum electromagnetic properties in the samples with x = 0.3: ɛr = 14.1, tan δe = 2.5 × 10−4, Hc = 47 A/m, 4πMs = 1936 × 10−4T, ΔH = 7.1 KA/m.

► Y3−xCaxZrxFe4.93−xO12 ferrite was developed by a solid-reaction method. ► The solubility of zirconium in the ferrite was approximately 0.3. ► The sample with x = 0.3 shows excellent electromagnetic properties. ► The substitution of Zr4+ for Fe3+ promotes grain growth of garnet phase. ► When x is 0.4, a second phase appeared.