A‐ and B‐Site Modified Perovskite Nanosheets and Their Integrations into High‐k Dielectric Thin Films

We investigated dielectric properties of perovskite nanosheets with different compositions ( Ca 2 − x Sr x Nb 3 − y Ta y O 10 ) to study the influence of A ‐ and B ‐site modifications on dielectric properties. L angmuir– B lodgett deposition was employed to fabricate multilayer nanofilms of perovskite nanosheets. In these nanosheets, the A ‐site modification by Sr 2+ ions causes the increase in ε r value, whereas the B‐ site modification with Ta 5+ ions improves leakage current characteristics and reduces permittivity value. The optimized property (ε r = 240) is obtained for Sr 2 Nb 3 O 10 nanosheet. We also discuss high‐ κ properties of Ca 2 − x Sr x Nb 3− y Ta y O 10 nanosheets by detailed investigations on first‐principles calculations and interfacial structures.