Dependence of the magnetoelectric coupling on elastic and dielectric properties of two-phase multiferroic composites

We report on temperature-dependent studies of ultrasonic and dielectric properties of (x)0.5(Ba0.7Ca0.3)Ti0(3)-0.5Ba(Ti0.8Zr0.2)O-3(BCZT)/(1 - x)NiFe2O4 (BCZT/NFO) composite multiferroics and their relationship to the magnetoelectric (ME) effect in these materials. The most decisive factor in the maximization of the ME effect is the strong elastic softening of the BCZT phase at the phase transition between its ferroelectric phases with orthorhombic and tetragonal symmetry. The proximity of this phase transition to room temperature makes the system promising for practical applications of the ME effect. The magnetostrictive phase does not play any direct role in the determination of the ME temperature dependence because of its weakly temperature-dependent mechanical properties.

Automated summary

This study investigates the temperature-dependent ultrasonic and dielectric properties of BCZT/NFO composite multiferroics and their relation to the magnetoelectric effect. The key factor in maximizing the magnetoelectric effect is the strong elastic softening of the BCZT phase at its ferroelectric phase transition. The temperature dependence of the magnetostrictive phase has little direct impact on the magnetoelectric effect.