The reactive partially ionized beam deposition technique was used to deposit amorphous BaxTi2−xOythin films with the Ba/Ti ratios from 1 for a stoichiometric BaTiO3film to 0.2 for a Ti enriched film. A postdeposition annealing between 500 and 600 °C converted stoichiometric amorphous BaTiO3into polycrystalline structure. This crystallization resulted in densification with a 9% decrease in film thickness. Off‐stoichiometric thin films remained amorphous up to 700 °C. Annealed off‐stoichiometric BaxTi2−xOyfilms, however, had lower leakage current and loss tangent than polycrystalline films due to their amorphous nature making them more suitable for electronic applications. At temperatures of 800 °C or higher, significant reaction occurred between the films and Si substrate as detected by Rutherford backscattered spectroscopy. ©1995 American Institute of Physics.