J. Phys. IV France 08 (1998) Pr9-73-Pr9-77
Preparation and properties of Ba1-xSrxTiO3 thin films deposited by the sol-gel techniqueE. Dien, R. Verveur, M. Lejeune and A. Smith
Laboratoire Matériaux Céramiques et Traitements de Surface (LMCTS - ESA 6015), École Nationale Supérieure de Céramique Industrielle (ENSCI), 47 à 73 avenue Albert Thomas, 87065 Limoges cedex, France
The present work concerns the preparation and the physical properties of Ba0.67Sr0.33TiO3 composition under thin film form. The layers have been deposited by spin-coating on top of Pt/Ti/SiO2/Si substrates using barium and strontium acetates, dissolved in acetic acid, mixed up with titanium tetra-isopropoxide in 2-propanol. The amounts of each constituent have been carefully adjusted to obtain stable and homogeneous sols. Different thermal treatments of the deposited layers have been carried out. They consist of a pre-firing cycle (330°C or 550°C) followed by a rapid thermal annealing (RTA) at 800°C. The final films are characterized by a thickness in the range 180-600 nm and an average crystallite size of 40 nm. This paper also presents the electrical characteristics of the deposits. So far, the best dielectric constant, εr, is of the order of 350. Variations of ε' and ε" with respect to temperature (from -20°C to 120°C) have been investigated.
© EDP Sciences 1998