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

• Good candidates for EM materials with low reflectivity.
• Good candidates for broad bandwidth at microwave frequency.
• Microwave absorbing bandwidth was modulated simply by manipulating the Zr–Mn.
• Higher the Zr–Mn content, the higher absorption rates for the electromagnetic radiation.
• The predicted reflection loss shows that this can be used for thin ferrite absorber.

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.

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