Temperature dependence of ferroelectric properties of SBT thin films

Strontium bismuth tantalate (SBT) thin films have been deposited on Pt/TiO2(100)Si substrates by a metal-organic decomposition (MOD) method, using a non-stoichiometric composition. The measured net spontaneous polarization is a consequence of the parallel alignment of 180 degrees domains, as it is confirmed by the random distribution of the pole figures. Measurements of temperature dependence of permitivitty, epsilon ', and remnant polarization, P-r, show diverse anomalies. The large shift of the temperature T-C, is explained by the structure distortion associated with Bi:Sr ratio of the film. A strong decrease Of P-r with T is observed that could be related with possible phase transitions, although more information on atomic level is needed to know the mechanisms involved. (C) 2001 Elsevier Science Ltd. All rights reserved.