Effects of Ca–Gd co‐substitution on the structural, magnetic, and dielectric properties of M‐type strontium hexaferrite.

Sr1−xCaxFe12−xGdxO19 (x = 0, 0.04, 0.08, 0.12, 0.16, 0.20) hexaferrites were characterized by several techniques, such as X‐ray diffraction, scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy, and vibrating sample magnetometer. Structural results indicate the formation of a pure‐phase Sr1−xCaxFe12−xGdxO19 hexaferrite with space group P63/mmc. SEM photography confirms that there are a smaller number of defects due to the reduced porosity and surface area (increased particle size). Magnetic investigations showed a rise of the coercive force from 5069.8 to 5757.4 Oe and saturation magnetization from 79.25 to 80.68 emu/g. The maximum values appear to be for sample x = 0.16, which may be useful in such as permanent magnets, and high‐density media for magnetic storage devices. Dielectric parameters, such as conductivity, the real part of permittivity, dielectric loss, dielectric tangent loss, and complex modulus, were studied. Impedance analysis shows that the conduction process is mainly governed by the long‐range movement of the charge carriers based on the Debye model for x = 0.12. [ABSTRACT FROM AUTHOR]