Dielectric and magnetoelectric properties of Li0.5Ni0.75-x/2Znx/2Fe2O4 + Ba0.5Sr0.5TiO3 ME composites

The magnetoelectric composites with the composition Y[Li0.5Ni0.75-x/2Znx/2Fe2O4] + (1 - Y)[Ba0.5Sr0.5TiO3] where x = 0.1, 0.2. 0.3 and Y = 0.1, 0.2, 0.3 were prepared by standard double sintering ceramic technique. The XRD patterns confirmed the coexistence of piezomagnetic and piezoelectric phases. Both dielectric constant (epsilon') and loss tangent (tan delta) decrease with increase in frequency exhibiting normal dielectric behaviour. The linearity in the log sigma(ac) vs. log omega(2) plots confirmed the small polaron hopping type of conduction mechanism in the composites studied. Flat curves in the ME output vs. dc magnetic field are obtained which may be due to the presence of strontium in the composites. ME output showed direct relation with the resistivity of the composites. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.