Structural transformation and ferroelectromagnetic behavior in single-phase Bi[sub 1-x]Nd[sub x]FeO₃multiferroic ceramics

Abstract

Single-phase Bi[sub 1-x]Nd[sub x]FeO₃ (BNFO[sub x]) (x = 0–0.2) multiferroic ceramics were prepared to study the effects of Nd substitution on their crystal structure and ferroelectromagnetic behavior. Rietveld refinement of x-ray diffraction data showed a continual transformation of crystal structure from the rhombohedral structure of BNFO[sub x = 0] (BiFeO₃) to a triclinic structure in BNFO[sub x = 0.05–0.15] and a pseudotetragonal structure in BNFO[sub x = 0.175–0.2]. Ferroelectromagnetic measurements revealed the existence of ferroelectricity with remnant polarization of ∼ 9 μC/cm² in BNFO[sub x = 0–0.175], paraelectricity in BNFO[sub x = 0.2], and weak ferromagnetism with remnant magnetizations of 0.07–0.227 emu/g in BNFO[sub x = 0.15–0.2]. Magnetoelectric coupling was obvious in BNFO[sub x = 0.15–0.175] near the Néel temperature of ∼ 380 °C.