Fabrication and magnetoelectric effect of 1-3 type composites with microscale (K,Na)NbO_3-based Pb-free piezoceramic pillars embedded in CoFe_2O_4-epoxy matrix

摘要

Microscale magnetoelectric composites with 1-3 connectivity structure were fabricated by a dice-and-fill method. Mechanically sliced microscale pillar arrays of (K,Na)NbO_3-based ceramics were used as the piezoelectric phase, which were embedded in a hybrid matrix composed of ferromagnetic CoFe_2O_4 particles bonded with epoxy. Commercial CoFe_2O_4 nano-powder and CoFe_2O_4 particles derived from a sol-gel method during the filling process were used in two sets of samples, respectively. Obvious ME response signals were detected to be switched with the applied magnetic field. It was deduced that the different ME coefficient values of the two composites were mainly due to the interface morphology between the piezoelectric pillars and the matrix.