Conduction mechanism and magnetic behavior of Cu doped barium hexaferrite ceramics

M-type barium hexaferrite ceramics (BaM) are important materials owing to their tremendous applications and useful properties. However magnetic and electrical properties of Cu substituted BaM haven't been studied yet. In the present study, Cu doped BaM samples having chemical formula BaFe12-xCuxO19 (where x = 0, 0.1, 0.3 and 0.5) were synthesized by conventional solid state mixed oxide route. X-ray diffraction and Fourier transform infrared spectroscopy confirmed the formation of hexagonal magnetoplumbite structure with space group P63/mmc as the major phase in all the samples. Scanning electron microscopy revealed the dense structure of undoped and doped samples with platelet-like morphology. Vibrating sample magnetometry showed a large decrease in the coercivity of BaM without the loss of saturation magnetization by the addition of Cu. Magnetic measurement at cryogenic temperature (25 K) revealed that Cu doped sample showed less variation in magnetic properties on decreasing the temperature as compared to undoped BaM samples. Room temperature dielectric studies showed that addition of Cu caused a decrease in dielectric loss however it increased at higher substitution level i.e. x = 0.5. High temperature conductivity studies revealed that single-ionized oxygen vacancies are responsible for conduction in Cu doped BaM.