Observation of strong magnetoelectric coupling and ferromagnetism at room temperature in Fe substituted ferroelectric BaZr0.05Ti0.95O3 thin films

Abstract

Single phase polycrystalline thin films (∼100 nm) of BaZr0.05(FexTi1−3x/4)0.95O3, with x = 0 (BZT) and 0.015 (BZFT15), were grown on Pt/TiO2/SiO2/Si substrate using pulsed laser deposition technique. Room temperature ferromagnetism with a remanent magnetization (Mr) ∼ 1.1 × 10−1 emu/cm3 and a coercive field (Hc) ∼ 0.1 kOe was observed in BZFT15 film. The ferroelectric domain switching in both BZT and BZFT15 films is confirmed by piezoresponse force microscopy (PFM). The magnetoelectric coupling coefficient (α) measured at room temperature in the BZFT15 film in in-plane magnetized-out of plane polarized configuration (L-T mode) was found to be ∼165 mV/cm Oe. It is argued that the observed ferromagnetism in BZFT15 films arises from the oxygen vacancy (Ov) mediated (Fe3+–Ov–Fe3+) exchange.