Direct magnetoelectric coupling in Pr doping Bi6Ti3Fe2O18 relaxor ferroics

Single-phase multiferroics are fractional and rarely meet at room temperature. Direct magnetoelectric coupling in relaxor ferroic phase was observed in Bi6−xPrxTi3Fe2O18 (x = 0.0, 0.3, 0.6, 0.9, and 1.2) films, where the chemical disorder doping-induced effective internal pressure played a key role. It is analytically formulated from the phase-structure shift, ferroelectric domain, and origin of the magnetic order. The strip magnetic domains are broken into a dotted domain structure following a quantitatively increase in lattice stress. A Monte Carlo simulation including stress energy items is used to unveil the hitherto unexplored coupling mechanism by tuning the symmetric exchange restriction of Fe3+–O–Fe3+. Moreover, the observation of coefficient 78.8 mV/cm·Oe at room temperature is intriguing for potential application.