Grain morphology dependent dielectric behaviour of ZnO – BaTiO3 composites

We report the effect of BaTiO3 (BTO) addition in ZnO on the dielectric behaviour of ZnO-BaTiO3 composite in the form of (1-x)ZnO–(x)BTO (x=0.2,0.3,0.4,0.5). Modifications in the structural and microstructural properties of the composite under study have been attributed to the addition of ferroelectric BTO in the host insulating ZnO matrix. Improvement in the overall dielectric performance of ZnO-BTO composite has been observed due to the increase in the dielectric constant and suppression of the dielectric loss. Study of dielectric behaviour of ZnO-BTO composite show that increasing in BTO concentration in ZnO matrix results in the grain boundary modifications and enhancement in relaxor behaviour which has been understood on the basis of percolation phenomena, wherein, BTO modifies the dipole arrangements leading to higher dielectric constant.