Magneto-dielectric anomaly in (Bi_(0.95)Nd_(0.05))(Fe_(0.97)Mn_(0.03))O_3 electroceramic

摘要

We report magneto-dielectric anomaly of the multiferroic (Bi_(0.95)Nd_(0.05))(Fe_(0.97)Mn_(0.03))O_3 (BNFM) ceramic near Neel temperature. The ceramic pellets were synthesized by conventional solid state reaction route. X-ray diffraction patterns revealed that most of the peaks shifted slightly towards higher Bragg's angle compared to those of pure BiFeO_3 and also confirmed the formation of rhombohedral phase. It also suggests that the small chemical substitution of Nd and Mn atoms at Bi and Fe sites of BiFeO_3 (BFO) perovskite respectively does not alter the crystal structure. Temperature and frequency dependent dielectric response indicate large dielectric anomaly at 620 K, slightly below the known Neel temperature of BFO. The enhancement in dielectric properties of BNFM ceramic was observed as compared to BFO due to suppression of oxygen vacancies by the doping. Temperature dependent dielectric response in conjunction with Raman and thermo-analytical data show that the BNFM sample presents significant magneto-dielectric response around Neel temperture T_N ～ 620 K.