Temperature dependence of magnetoelectric effect in Bi 3.15Nd0.85Ti3O12-La 0.7Ca0.3MnO3 multiferroic composite films buffered by a LaNiO3 layer

Multiferroic composite thin films were fabricated based on ferroelectric (FE) Bi3.15Nd0.85Ti3O12 (BNT) and ferromagnetic (FM) La0.7Ca0 3MnO3 (LCMO) parents with different growth sequences of BNT-LCMO/LNO/STO (BL) and LCMO-BNT/LNO/STO (LB). Ferroelectric behaviour along with remnant polarization (2P(r)) of 50 mu C cm(2) and 40 mu C cm(2) at room temperature, saturated magnetization values around 206 emu cm(-3) and 192 emu cm(-3) at 100 K were measured for BL and LB composite films, respectively. The temperature dependence of the magnetoelectric (ME) coupling effect was investigated and the ME voltage coefficients of 63 mV cm(-1) Oe(-1) and 60 mV cm(-1) Oe(-1) at 100 K were respectively obtained for the BL and LB films. The results show that the composite films exhibit both good ferroelectric and ferromagnetic properties, as well as a substantial ME effect. Moreover, it is demonstrated that the layer sequences and temperature have significant impacts on the magnetoelectric coupling behaviour of these double-layered thin films, which is very likely caused by the magnetic-mechanical-electric interaction, substrate clamping and interface coupling.