New Trends in Physical Science Research Vol. 2

Abstract

We report the investigation of structural, magnetic, dielectric and magnetodielectric properties of orthorhombic Bi_2(1-x)Gd_2xFe₄O₉ (x = 0, 0.015) ceramics synthesized by the solid state reaction route. Room temperature Rietveld refinement of X-ray diffraction pattern of the ceramics shows structural distortion due to lower ionic radii Gd³⁺ (1.05 Å) substitution at Bi³⁺ (1.17 Å) site. Magnetic measurements confirmed an enhanced antiferromagnetic transition temperature (T_N) in x = 0.015 (254 K) as compared to the BFO (250 K) along with an increase in magnetization due to the coupling between Gd³⁺ and Fe³⁺ ions. A concomitant anomaly in dielectric and tan loss plot around magnetic transition temperature indicated plausible magnetoelectric coupling (MEC) in both the samples and the MEC coefficient (Y) is approximated by ~ YM². Enhanced magnetodielectric response (~100 %) has been observed for x = 0.015.