Microwave absorption behavior of Gd-doped spinel ferrites at high frequencies

Abstract

The spinel ferrites (SFs) are renowned for their distinctive magnetic and electrical characteristics. Sol-gel route was used for the fabrication of Sr_0.6 Zn_0.4 Gd_x Fe_2-x O₄ (0.00, 0.025, 0.050, 0.075, 0.100) ferrites. The structural, magnetic, microwave, and DC (direct current) properties of prepared Nps were found using of number characterization techniques. The X-ray diffraction (XRD) pattern of Sr_0.6 Zn_0.4 Gd_x Fe_2-x O₄ SFs showed a single cubic phase. The magnetic behavior was determined by applying a field of 2 kOe. The various magnetic features, including those determined based on the M-H loop, and prepared spinel ferrites showed the soft nature of magnetic materials. When amount of gadolinium (Gd) is increased, then saturation magnetization, coercivity, remanence magnetization is decreased. The Ms values decreased from 69.36 to 32.18 emu/g, coercivity reduced from 220 to 14 emu/g, and remanence magnetization is decreased from 32 to 3 emu/g. The electrical parameters revealed that direct current resistivity and activation energy (Ea) increased (from 0.16 eV to 0.28eV) with the inclusion of the Gd. The activation energy was increased from 0.16 to 0.28 eV. The dielectric constant and loss of permittivity and permeability were determined by applying the frequency 5.5–9.5 GHz. From the above enhanced parameters, it can be concluded that fabricated SFs may be suitable for high-frequency devices.