Study of magnetic, elastic and Ka-band absorption properties of Zn1−xCoxFe2O4 (0.00 ≤ x ≤ 1.00) spinel ferrites

Abstract

Magnetic, elastic, electromagnetic, and microwave absorption properties of cobalt-substituted zinc spinel ferrites Zn1-xCoxFe2O4 (0.00 ≤ x ≤ 1.00, Δx = 0.25) fabricated via the sol–gel citrate route are analyzed. The hysteresis loops of constituent ferrites revealed the rapid rise in saturation magnetization and coercivity with the doping of cobalt ions. The FT-IR spectra exhibit two vibrational bands in the scope of 521–560 cm−1 and 397–404 cm−1. Complex permittivity (ɛr) and complex permeability (µr) are analyzed using a vector network analyzer in Ka-band. The absorption is maximized by tuning the thickness of the sample from 0.8 mm to 3.5 mm using the quarter wavelength model. Maximum absorption of 99.14 % at a matching frequency of 34.60 GHz and a matching thickness of 1 mm is obtained by the composition with × = 0.75. The prepared ferrite composition proves to be an efficient microwave-absorbing material at high frequencies ranging from 26.5 to 40 GHz.