KNaNbO3-LiTaO3-LiSbO3 Thin Films by Pulsed Laser Deposition

Morphotropic phase boundary composition KNaNbO₃-LiTaO₃-LiSbO₃ (KNN-LT-LS) thin films were grown by pulsed laser deposition on niobium doped conductive SrTiO₃ substrates. Using X-ray diffractometry, the phase evolution, stoichiometry, and growth orientation were monitored for various deposition conditions including temperature and ambient oxygen partial pressure. The results indicate that the scattering of the cations such as potassium, sodium, and lithium by the oxygen molecules is a very critical factor in the formation of the secondary phases in the films. We report thin films with a good crystallinity grown at 650degC and in ambient oxygen partial pressure. On 1 micron films, a longitudinal relative permittivity of 500, along with a loss tangent of 0.5% at 1 MHz has been obtained.