Effect of Gd doping on the structural, magnetic and dielectric properties of Y-type hexaferrite BaSrCo2(Fe1-xGdx)11AlO22 ceramics

In this study, the impact of Gd3+ doping on the structural, magnetic and dielectric properties of BaSrCo2(Fe1- x Gd x ) 11 AlO 22 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) ferrite ceramics synthesized by the conventional solid-state reaction method are investigated. XRD results reveal that all the samples crystallize in the R 3 m space group. With the increase of Gd content, the formation of M-type phase is effectively inhibited due to Gd3+ ions may change the activation energy of nucleation of the grains and the formation energy of hexaferrite. SEM analysis confirms the presence of hexagonal grains in samples with homogeneous elements distribution. The XPS results verify the coexistence of ferric and ferrous ions in the ceramics. The magnetization and coercivity are suppressed by Gd3+ substitution. The permeability increases firstly and then decreases with the substitution of Gd ions. While the dielectric constant increases with the substitution of Gd. The real and imaginary parts of the dielectric constant in the frequency range of 2-18 GHz change slightly with doping amounts variation, and all the samples exhibit prominent peaks at about 14 GHz due to natural resonance.