Enhanced Magnetodielectricity In Gd~(3+) Substituted Bi_2Fe_4O_9 Ceramics

摘要

We report the synthesis of orthorhombic Bi2(_(1-x))Gd2_kFe_4O_9 (x=0, 0.015) ceramics by solid state route and have investigated its structural, magnetic, dielectric and magnetodielectric properties. Rietveld refinement of X-ray diffraction pattern at room temperature shows structural distortion due to lower ionic radii substitution. Magnetic measurements confirmed an enhanced antiferromagnetic transition temperature (T_N) in x= 0.015 (254 K) as compared to the parent sample (250 K) along with an increase in magnetization due to the coupling between Gd~(3+) and Fe~(3+) ions. A concomitant anomaly in dielectric (ε') and tan loss plot around T_N indicated plausible magnetoelectric coupling (MEC) in both the samples and the MEC coefficient (y) is approximated by~ yM~2. The highest value of the magnetodielectric response (~100% enhancement) has been observed forx=0.015 sample.