Year: 2015
Type: article
Abstract: $\mathrm{SrV}{\mathrm{O}}_{3}$ and $\mathrm{SrNb}{\mathrm{O}}_{3}$ are perovskite-type transition-metal oxides with the same ${d}^{1}$ electronic configuration. Although $\mathrm{SrNb}{\mathrm{O}}_{3}$ $(4{d}^{1})$ has a larger $d$ orbital than $\mathrm{SrV}{\mathrm{O}}_{3}$ $(3{d}^{1})$, the reported electrical resistivity of $\mathrm{SrNb}{\mathrm{O}}_{3}$ is much higher than that of $\mathrm{SrV}{\mathrm{O}}_{3}$, probably owing to nonstoichiometry. In this paper, we grew epitaxial, high-conductivity stoichiometric $\mathrm{SrNb}{\mathrm{O}}_{3}$ using pulsed laser deposition. The growth temperature strongly affected the Sr/Nb ratio and the oxygen content of the films, and we obtained stoichiometric $\mathrm{SrNb}{\mathrm{O}}_{3}$ at a very narrow temperature window around 630 \ifmmode^\circ\else\textdegree\fi{}C. The stoichiometric $\mathrm{SrNb}{\mathrm{O}}_{3}$ epitaxial thin films grew coherently on $\mathrm{KTa}{\mathrm{O}}_{3}$ (001) substrates with high crystallinity. The room-temperature resistivity of the stoichiometric film was $2.82\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}\phantom{\rule{0.16em}{0ex}}\mathrm{\ensuremath{\Omega}}\phantom{\rule{0.16em}{0ex}}\mathrm{cm}$, one order of magnitude lower than the lowest reported value of $\mathrm{SrNb}{\mathrm{O}}_{3}$ and comparable with that of $\mathrm{SrV}{\mathrm{O}}_{3}$. We observed a $T$-square dependence of resistivity below ${T}^{*}=180\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and non-Drude behavior in near-infrared absorption spectroscopy, attributable to the Fermi-liquid nature caused by electron correlation. Analysis of the $T$-square coefficient $A$ of resistivity experimentally revealed that the $4d$ orbital of Nb that is larger than the $3d$ ones certainly contributes to the high electrical conduction of $\mathrm{SrNb}{\mathrm{O}}_{3}$.
Source: Physical Review B
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2215876381