A-Site-Modified Perovskite Nanosheets and Their Integration into High-$\kappa$ Dielectric Thin Films with a Clean Interface

We investigated dielectric properties of La 1-x Eu x Nb 2 O 7 perovskite nanosheets in order to study the effect of A -site modification on dielectric properties. Langmuir--Blodgett deposition was employed to fabricate multilayer nanofilms of perovskite nanosheets. In these nanosheets, A -site modification with Eu 3+ ions improves the leakage current characteristics and, at the same time, reduces permittivity. The slight modification with Eu 3+ ions in La 0.95 Nb 2 O 7 nanosheets causes a 50% reduction in $\varepsilon_{\text{r}}$ value. We also discuss the high-$\kappa$ properties of La 0.95 Nb 2 O 7 nanosheets by performing detailed investigations based on first-principles calculations and interfacial structures.