Structural, physicochemical and electrical properties of Co2Y-type barium hexaferrites

Abstract

Y-type hexaferrite ceramic materials of nominal composition Ba2Co2CrxYxFe12-2xO22 (x = 0.00, 0.03, 0.06, 0.09, and 0.12) were synthesized by sol-gel auto combustion route. Y-type hexaferrites are technologically important ceramic materials for fabricating modern electronic devices and microwave absorbers due to their unique electrical and dielectric properties and reflection loss behavior. XRD classifies the single-phase formations with space group R 3‾ m. The crystallite size of the synthesized samples was calculated in (34–41) nm range. The specific absorption band in FTIR spectra approves the (Fe–O) stretching vibrations at wavenumbers 446 and 478 cm−1. The substitution of iron by Cr3+ and Y3+ increases DC resistivity from 1.03 × 1011 to 1.17 × 1012 Ω cm by limiting the electrons jumping between ferrous and ferric ions. The activation energy and drift mobility were also calculated among the substituting content of Cr3+-Y3+. The dielectric response in 1 MHz–6 GHz frequency was determined and the effect of substitution has been observed. The Maxwell-Wagner (MW) bilayer model is used to study dispersion in dielectric parameters with reference to applied frequency. The maximum values of dielectric losses were obtained at 6 GHz in the range of 0.37–0.60. The coercivity values confirms the soft magnetic nature of synthesized samples. The microwave absorption (MW) properties of synthesized materials were improved upon Cr3+-Y3+ substitution. Minimum reflection loss RLmin = −66 dB (99.99% absorption of MW) at 1.46 GHz frequency and 1.96 mm thickness was obtained for x = 0.09 composition. All investigated samples are efficient materials for stealth technology, radar cross-reduction, EM interference shielding, and high-frequency applications.