Influence of B2O3 on the Broadband Electromagnetic Response of MgFe1.98O4 Ceramics

Abstract

MgFe1.98O4 ceramic has been synthesized by a solid-state reaction route, and the effect of different concentrations of B2O3 (0.5 wt.%, 1 wt.%, 2 wt.%, and 5 wt.%) on its broadband electromagnetic response is investigated. B2O3 acts as a liquid-phase sintering aid that reduces the sintering temperature of MgFe1.98O4 to 1100°C without changing the bulk density. X-ray diffraction analysis confirms that MgFe1.98O4 ceramic is phase pure even after the addition of B2O3. The vibrational modes are identified using Raman and Fourier transform infrared (FTIR) spectroscopic analysis. The disorder effect and the associated splitting that occurred in the Raman modes confirm the inverse spinal structure of B2O3-modified MgFe1.98O4 ceramics. The compositions with 1 wt.% and 2 wt.% of B2O3 have real permittivity of 8.9 and 9.8, real permeability of 4.7 and 6.2, respectively, and reasonably low dielectric loss of the order of 10−1 at 100 MHz. Further, 1 wt.% and 2 wt.% B2O3 added compounds show room-temperature saturation magnetization of 26.1 and 25.6 emu/g and coercive field strength of 20 and 23 Oe, respectively. The broadband electromagnetic response shows that MgFe1.98O4 with 1 wt.% and 2 wt.% B2O3 can be used as a suitable substrate material for antenna fabrication.