Lithium tantalate (LiTaO3) thin films were deposited on ruthenium dioxide (RuO2) electrode by reactive radio frequency (RF) magnetron sputtering with a lithium dioxide-tantalum pentoxide (Li2O2/Ta2O5) (50-50% mole ratio) target. This article presents morphological, structural, dielectric and pyroelectric studies of LiTaO3 thin films as function of growth conditions (RF power, gas pressure and temperature). The final aim is to improve the pyroelectric coefficient for thermal detectors applications. The best pyroelectric coefficient of LiTaO3 thin films (400 nm) equal to 60 mu C/m(2) K was obtained for a growth temperature of 400 degrees C, and a pressure of 10 mTorr. (C) 2007 Elsevier B.V. All rights reserved.