EFFECTS OF SINTERING TEMPERATURE AND TIME ON GRAIN-SIZE AND DIELECTRIC-CONSTANT OF POTASSIUM TANTALUM NIOBATE FILMS

Thin films of potassium tantalum niobate (KTN) formed by metalorganic deposition were subjected to one- and two-step sinterings in air and potassium atmosphere. These polycrystalline films were found to be mechanically robust and display electrical properties similar to single-crystal KTN. This report shows that film grain size increased with sintering temperature and time. Scanning electron micrographs revealed grain sizes ranging from submicrometer to 5 mum in diameter. The maximum relative permittivity, its corresponding rate of change with temperature, and film grain size were measured as a function of sintering temperature and time.