Comprehensive dielectric performance of alternately doped BST multilayer films coated with strontium titanate thin layers

It is a huge difficulty to improve the comprehensive dielectric performance of barium strontium titanate (BST) films for applications in energy storage, microwave, etc. Herein, on Pt/Ti/SiO2/Si substrate strontium titanate (ST), manganese (Mn) doped BST and yttrium (Y) doped BST layers were attempted to be designed as ST/MnBST/YBST/ … /MnBST/YBST/ST films and prepared by a modified sol–gel method, and structures and performances of the films were studied. X-ray diffraction shows that the films are ABO3 perovskite polycrystalline with Ti4+ at B sites replaced by some Mn2+ and exhibit dense nodular microstructures observed by a scanning electron microscope. The films exhibit optimized comprehensive performance with leakage current density of less than 1E-10 A/cm2 at 20 V and dielectric losses of 0.3%–0.4% at 100 kHz and about 1.8% at 1 GHz, meeting the needs of some applications.