Influence of deposition temperature on structural and ferroelectric properties of Bi4Ti3O12 thin films

Bismuth titanate thin films were deposited using in situ layer-by-layer reactive DC magnetron sputtering. Films were deposited on platinized silicon (Pt/Ti/SiO2/Si) substrates at the temperature of 400-500 degrees C. The study focused on the dependency of structural, morphological and ferroelectric properties on the parameters of material growth. Thin films, which were formed at the temperature of 450-500 degrees C, have dense columnar structure and flat surface. Hysteresis measurements revealed the ferroelectric nature of some of the studied films, except for the films deposited at the temperature lower than 450 degrees C. It was demonstrated that the volatility of bismuth oxide is affected by the temperature starting at 475 degrees C. The highest coercive field and remnant polarization of E-c = 130 kV/cm and of P-r = 73 mu C/cm(2) was obtained for film deposited at 450 degrees C. It appeared that the shape was clearly influenced by a certain extrinsic contribution (other than leakage) which produces an overestimation of the remnant polarization. Based on the results of the current leakage data investigation, it was established that films exhibit the space charge limited conduction. (C) 2016 Elsevier B.V. All rights reserved.