Magnetic characterization of Ca substituted Ba and Sr hexaferrites

A magnetic characterization has been worked out for the solid solution from Ba and Sr hexaferrites (BaFe_{1 2}O_{1 9}, SrFe_{1 2}O_{1 9}) towards CaO-xFe₂O₃ (2 ? x ?5.5). Measurements of Curie temperature, saturation magnetization, magnetic anisotropy, together with Mössbauer characterization indicate that the intrinsic properties of the studied compounds do not change appreciably with increasing Ca content. These results, together with the X-ray data, are consistent with the formation of an undistorted M-type cell with a low content of iron and oxygen vacancies.