Permeability and electromagnetic wave absorption properties of sintered barium hexaferrites with substitution of Co2+-Zr4+

The Co2+-Zr4+ substituted M-type barium hexaferrites with the chemical formula BaCoxZrxFe12-2xO19 (x = 0.0, 0.3, 0.6, 0.9 and 1.2) were synthesized by a sol-gel auto-combustion method. The structural characterizations of the prepared samples were studied using X-ray diffraction and scanning electron microscopy. The complex permeability (mu = mu' - j mu aEuro(3)) was measured on sintered samples in the frequency range of 100 MHz-3 GHz, and the electromagnetic wave absorbing characteristics of the prepared ferrites with various x value were evaluated from measurements of complex permeability. The results showed that the value of mu and the resonance frequency can be justified by controlling the substituting contents of Co2+-Zr4+. The reflection loss calculations showed that Co2+-Zr4+ substituted barium hexaferrites are good EM-wave absorbers in the quasi-microwave band (1-3 GHz).