Pyroelectricity of spontaneously poled La-modified lead titanate thin films on silicon based substrates

Multiple deposition by spin-coating and RTP crystallisation have been used to obtain La-modified lead titanate thin films of composition Pb0.88La0.08T iO3 (PTL) onto two types of substrates: Ti/Pt/Ti/(100)Si annealed at 650 de greesC and Pt/TiO2/(100)Si. The films on Ti/Pt/Ti/(100)Si present a main < 111 > preferred crystallographic orientation, whereas the films on Pt/TiO2/ (100)Si present a mixed < 001 > / < 100 > preferred orientation. All the fi lms developed a net polarisation in the direction perpendicular to the film plane and a spontaneous pyroelectric coefficient. The hysteresis and switc hing characteristics of the filins were dependent on the type of substrate. Results as a function of the number of deposited layers are presented. Pol ing was carried out under different electrical signals at 150 degreesC. The highest pyroelectric coefficient achieved at room temperature was gamma si milar to 40 x 10(-9) C cm(-2) K-1. (C) 2001 Elsevier Science Ltd. All right s reserved.