Preparation and Characterization of W-Type Hexaferrite Doped with La

A series of W-type ferrites with the composition of Ba_1-x,La_xCo₂Fe₁₆O₂₇(where, x =0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) were prepared by solid-state reaction method. The structure transformations of the ferrites were examined by XRD, DTA-TG and XPS, and the microwave-absorbing properties were investigated by evaluating the permeability and permittivity of materials (μ_{x r}). The results showed that the phase-transition temperature increased with the addition of La³⁺ content, and a single-phase was formed at 1250 °C at last. Microwave properties were obviously improved as a result of the substitution of La³⁺ for Ba²⁺ at the frequency range of 0.5 18.0 GHz.