Microwave absorbance properties of zirconium-manganese substituted cobalt nanoferrite as electromagnetic (EM) wave absorbers

Nanocrystalline Zr-Mn (x) substituted Co ferrite having chemical formula CoFe2-2xZrxMnxO4 (x = 0.1-0.4) was prepared by co-precipitation technique. Combining properties such as structural, electrical, magnetic and reflection loss characteristics. Crystal structure and surface morphology of the calcined samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). By using two point probe homemade resistivity apparatus to find resistivity of the sample. Electromagnetic(EM) properties are measured through RF impedance/materials analyzer over 1 MHz-3 GHz. The room-temperature dielectric measurements show dispersion behavior with increasing frequency from 100 Hz to 3 MHz. Magnetic properties confirmed relatively strong dependence of saturation magnetization on Zr-Mn composition. Curie temperature is also found to decrease linearly with addition of Zr-Mn. Furthermore, comprehensive analysis of microwave reflection loss (RL) is carried out as a function of substitution, frequency, and thickness. Composition accompanying maximum microwave absorption is suggested. (C) 2013 Elsevier Ltd. All rights reserved.