Response of dielectric behaviour on ferroelectric rich (y) Ni0.8Zn0.2Fe2O4+(1-y) PZT ME composites

The magnetoelectric (ME) composites consisting of ferrite and ferroelectric phases viz. (y) Ni0.8Zn0.2Fe2O4 + (1 - y) PbZr0.52Ti0.48O3 (PZT) in which y varies as 0, 0.15, 0.30, 0.45 and 1 mol% were prepared by a conventional double-sintering ceramic method. The presence of two phases in composites was confirmed by XRD technique. The variation of dielectric constant (epsilon) and loss tangent (tan delta) with frequency in the range 20 Hz-1 MHz at room temperature and also with temperature at four different frequencies (viz.1 kHz, 10 kHz, 100 kHz, and 1 MHz) were studied. The detailed studies on the dielectric properties were done presuming that the magnetoelectric interaction between constituent ferrite and ferroelectric phases may result in various anomalies in the dielectric behaviour of these composites. Ac conductivity measurements were carried out to determine the nature of charge carriers during conduction. The value of static magnetoelectric conversion factor (dE/dH)(H) was measured as a function of intensity of applied dc magnetic field. The maximum value of ME voltage coefficient viz. 769 mu V cm(-1) Oe was observed for a 15% Ni0.8Zn0.2Fe2O4 + 85% PZT composite. (C) 2007 Published by Elsevier B.V.