Ca(Mg1/3Ta2/3)O3 dielectric thin films: preparation, structure, mechanical and dielectric properties

The effects of annealing temperature on the crystallinity, grain size and hence mechanical and dielectric properties of Ca(Mg1/3Ta2/3)O3 (CMT) dielectric films were systematically studied. The CMT thin films were fabricated by an aqueous solution-gel technology and exhibited uniform, smooth and dense morphologies. The optimum pyrolysis temperature and time was 550 °C and 330 s, respectively. All the CMT films annealed from 650 to 800 °C show a single perovskite phase and the crystallization increases with increasing the annealed temperature but a secondary phase is observed in the film annealed at 900 °C. The hardness and reduced modulus were effectively enhanced by increasing the annealing temperature, which can be correlated to the crystallinity and densification improvements. Higher elastic recovery was observed for CMT films annealed at higher temperatures indicating less difficult recoveries for those films. We also noticed that the dielectric constants were improved for the samples annealed at higher temperature, which may enable higher performances for future microwave communication electronics.