Great enhancement of polarization in the (Ba0.67Sr0.33TiO3/LaNiO3)n multilayer thin films

The periodic (Ba0.67Sr0.33TiO3/LaNiO3)(n) multilayer thin films were prepared on Pt (111)/SiO2/Si (100) substrates by radio-frequency magnetron sputtering technology. It is found that the electric polarization of the thin films can be enhanced by the periodic hetero-structures strongly. For the five periods multilayer thin films, the frequency dependence of the apparent dielectric constant show almost constant high values of dielectric constant (> 2100) and relatively low loss tangent (<0.1) below 10 kHz. The remanent polarization (P-r) and the max polarization (P-max) obtained from the P-E hysteresis loops, are 15.4 mu C/cm(2) and 66.2 mu C/cm(2), respectively. The temperature dependencies of the pyroelectric coefficients were measured by a dynamic technique. The intrinsic pyroelectric coefficient and material merit figure of the periodic BST/LNO multilayer films are 4.93425 x 10(-8) C cm(-2) K-1 and 0.39 x 10(-5) Pa-1/2. (C) 2016 Elsevier B.V. All rights reserved.