Solution-based fabrication of perovskite multilayers and superlattices using nanosheet process

We report a solution-based fabrication of perovskite multilayers and superlattices using perovskite nanosheets. Perovskite nanosheets (LaNb ₂O₇, Ca₂Nb₃O₁₀, and Sr₂Nb₃O₁₀) were prepared by delaminating layered perovskites. A layer-by-layer approach using Langmuir-Blodgett deposition was effective for fabricating high-quality nanofilms of perovskite nanosheets on various substrates, such as quartz glass, Si, and SrRuO ₃. Structural characterizations by X-ray diffraction, transmission electron microscopy, and hard X-ray photoelectron spectroscopy revealed that these perovskite nanofilms are composed of a well-ordered lamellar structure with an atomically sharp interface. The multilayer films exhibited a stable dielectric response inherent to the perovskite nanosheet. We also found that the superlattices of (LaNb₂O₇/Ca₂Nb ₃O₁₀)₅ and (Sr₂Nb₃O ₁₀/Ca₂Nb₃O₁₀)₅ possess strong interface coupling, which gives rise to enhanced dielectric constant.