Effect of annealing process on properties of CaBi4.3Ti4O15 ferroelectric thin films

CaBi4.3Ti4O15 ferroelectric thin films were fabricated by sol-gel method with rapid thermal annealing technique on Pt/Ti/SiO2/Si substrates. It was found that annealing process influenced greatly on growth behavior and microstructure and polarization feature of CaBi4.3Ti4O15 thin films. The patterns of X-ray diffraction exhibited that the CaBi4.3Ti4O15 thin films annealed at 750°C is a-axis-orientation. Furthermore, the properties of CaBi4.3Ti4O15 thin films also depend on annealing environment. The films annealed in O2 show the hysteresis loop with remnant polarization and coercive field of 21.4μC/cm2 and 27.7kV/mm, respectively. Dielectric properties of the samples were also measured, showing dielectric constant Εr = 250±4% and dielectric loss tanδ = 0.005-0.01 over the range of 1-1MHz. That can be attribute to that O2 inhibited oxygen vacancies formation.