Microstructure-property relationship in magnetoelectric bulk composites

We present systematic studies that comprise phase connectivity and dielectric, multiferroic (MF) and magnetoelectric (ME) properties of (x) Ni0.8Co0.2Fe2O4+(1 - x)Pb(Mg1/3Nb2/3)(0.67)Ti0.33O3 [where x = 0.15, 0.30 and 0.45] ME composites prepared by conventional solid-state reaction method. Scanning electron microscopic images of the composites predict different types of connectivity schemes viz 3-0, 3-1 and 3-3. The phase transition temperature of PMN-PT is independent of Ni0.8Co0.2Fe2O4 content. Room temperature P-E and M-H loops indicate the simultaneous existence of ferroelectric/magnetic ordering. In order to study the possibility of monitoring electrical ordering by means of a magnetic field, ME measurements were carried out. The composition-dependent phase connectivity was well co-related to formation of percolation path and inturn magnetoelectric output. (C) 2010 Elsevier B.V. All rights reserved.