Cr³⁺ doping-controlled magnetic and dielectric properties of polycrystalline Y-type BaSrCo₂Fe_11-xCr_xAlO₂₂ hexaferrite

The trend towards multifunctionality and integrating electronic devices has led to the exploration of Y-type hexaferrite with excellent magnetic and dielectric properties. The Y-type hexaferrite BaSrCo2Fe11-xCrxAlO22 (0.0 <= x <= 0.5, with step of 0.1) ceramics have been prepared by conventional solid state reaction route. The phase structure, microscopic morphology, magnetic and dielectric properties of Y-type hexaferrite with chromium substitution are studied in detail. The analysis of XRD, SEM and EDS reveals that the lattice parameters and grain size decrease with the increase of Cr content. XPS results show the coexistence of Fe2+ and Fe3+. All samples exhibit well-defined ferromagnetic hysteresis loops at room temperature and the Cr3+ doping enhances the saturation magnetization and coercivity. The dielectric constants for all samples are found in the range of 10-15 and the dielectric loss is less than 0.02 at high frequency. The resistivity demonstrates that the samples possess high insulating nature with all above 2 x 10(9) ohm center dot cm, with a maximum value of 9.5 x 10(9) ohm center dot cm for x = 0.2. These results reveal that Cr3+ doped Y type hexaferrite could have potential applications in multifunctional electronic devices.