Room-temperature magnetoelectric coupling in single-phase BaTiO3-BiFeO3 system

In this paper, single-phase multiferroic ceramics of (1 − x) BaTiO3 − x BiFeO3 (BT − x BFO) were synthesized by solid-solution method in the wide range of material composition (x = 0.025 – 1.0). The changes in crystal structure were confirmed via X-ray diffractions (XRD) and atomic pair distribution functions (PDFs). The room-temperature ME coupling was found to exhibit significant magnitude in the narrow composition window (x = 0.71 – 0.8) where the average crystal structure was found to be rhombohedral. Especially, the BT – 0.725 BFO ceramics containing local monoclinic distortions within rhombohedral phase were found to exhibit high room-temperature ME coefficient (αME) of 0.87 mV/cm·Oe with high piezoelectric properties (g33 = 18.5 × 10 mV m N−1 and d33 = 124 pC N−1). We believe that the high room-temperature ME coupling in single-phase lead-free BT-BFO ceramics provides a possibility of developing electrically or magnetically tunable thin-film devices.