Evaluation of ferroelectricity in BaTiO3 epitaxial thin film using Ca(Mn,Nb)O-3 bottom electrode for high-temperature annealing

Due to epitaxial strain, epitaxial thin films exhibit unique properties compared with those in bulk. However, the presence of defects within these films disrupts the strain-induced effects. Although high-temperature annealing is a promising way to improve film quality, high temperature weakens bottom electrode materials. To assess epitaxial strain's effects on the mitigation of other factors, there is a need for a novel bottom electrode material that can withstand high temperatures. In this study, we focused on Nb-doped CaMnO3 (CMNO) as a bottom electrode for the evaluation of BaTiO3 ferroelectricity. The CMNO epitaxial film was deposited on (100)SrTiO3 and showed electrical conductivity even after 1100 ?annealing. The ferroelectric material BaTiO3 was also epitaxially grown on CMNO/(100)SrTiO3 substrate, and its ferroelectric properties were evaluated. Finally, we revealed the ability of CMNO/(100)SrTiO3 to withstand temperatures up to 1100 ? as well as the notable enhancement of ferroelectric properties in the BaTiO3 film.

Automated summary

Epitaxial thin films have unique properties due to epitaxial strain, but the presence of defects disrupts these effects. High-temperature annealing can improve film quality, but weakens bottom electrode materials. This study focused on Nb-doped CaMnO3 as a bottom electrode to evaluate BaTiO3 ferroelectricity, demonstrating the ability to withstand high temperatures and enhance ferroelectric properties.