Effect of Sn doping on the room temperature magnetodielectric properties of yttrium iron garnet

The structures, magnetic properties, permittivity spectra, and magnetodielectric (MD) effects of polycrystalline Y3Fe5−xSnxO12 compounds prepared by solid state reactions were systematically investigated. The substitution of Sn4+ leads to lattice expansion and the donation of excess electrons in ceramics, which affects the concentration of Fe2+, space charge, and electric dipole. As a result, as the amount of Sn dopant increases, so does saturation magnetization and permittivity in the low frequency band. The MD coefficient ([er(H) − er(0)]/er(0)) of lightly doped samples (x ≤ 0.05) is negative in the entire frequency band, reaching −2.3% at 350 MHz and 0.6 T for Y3Fe4.95Sn0.05O12 ceramics. The MD coefficient of heavily doped samples (x > 0.05) is positive in the low frequency band, reaching 0.83% at 10 MHz and 0.6 T for Y3Fe4.925Sn0.075O12 ceramics, and then decreasing with the increasing frequency, gradually becoming negative in the high frequency band. A detailed explanation is provided based on the or...