Effect of coalesce doping of Nd and La on structure, dielectric, and magnetic properties of BiFeO₃

Abstract

Single phase Bi_0.9-xLa_0.1Nd_xFeO₃ (BLNFO_x) (x=0.05, 0.07, and 0.1) multiferroic ceramics were prepared to study the effect of combine substitution of La and Nd in BiFeO₃ (BFO). X-ray diffraction studies revealed phase transition from rhombohedral (R3c) to triclinic (P1) on substitution of 05 and 07 mol% of Nd and subsequent transition to monoclinic C2/c with 10 mol% of Nd along with 10 mol% of La. These structural phase transitions and weakening of long range ferroelectric order with increasing x are also confirmed from Raman spectra. The existence of ferroelectricity and the corresponding Curie temperature for all noncentrosymmetric composition were determined using differential thermal analysis. Small remnant magnetization of 0.067 emu/g is observed in (BLNFO)_x=0.07 as a result of collapse of space modulated spin structure. For pure BFO dielectric anomaly was observed at 355°C corresponding to Neel temperature. Due to coexistence of long range ferroelectric order and canted antiferromagnetic orders in (BLNFO)_{x=0.05 and 0.07} the magnetoelectric effects were observed below Neel temperature at 302 and 294°C, respectively, near which magnetoelectric coupling is obvious.