Influence of nonuniform internal stress on magnetoelectric coupling in bilayers of ferromagnet/ferroelectrics

Abstract

The influence of nonuniform internal stress on magnetoelectric coupling in bonded layered composites of ferromagnet and ferroelectrics was discussed. The distribution of the inner stress in the ferroelectrics layer under an applied field was studied. A new expression for the magnetoelectric voltage coefficients (MEVC) was obtained through extending Harshe's model, which was derived based on a uniform internal stress in the ferroelectric layer, to the cases with non-uniform internal stresses. The MEVC from the new model is evidently less than that obtained from Harshe's model. According to the new model, one can explain why the observed MEVC values were much less than that calculated from Harshe's model.