Abstract
The crystallographic orientation, microstructure and electrical properties of Sr2(Ta, Nb)2O7 thin films strongly depended on the composition (Ta:Nb). Post-annealing at 850°C was effective for the improvement of some properties. The thin films with relatively Nb-rich compositions, such as Sr2(Ta0.6Nb0.4)2O7 and Sr2(Ta0.5Nb0.5)2O7, showed the (0k0) preferred orientation. The Sr2(Ta0.5Nb0.5)2O7 thin film had a lamination layer structure after the post-annealing at 850°C for 6 min in oxygen. The characteristic microstructure originated in the crystallographic orientation of (0k0), which is the cleavage plane, and influenced electrical properties. The dielectric constant little change with the composition, however, the P-E hysteresis properties improved with the Nb content.