Year: 2006
Type: article
Abstract: We investigated the electronic structures of the two-dimensional layered perovskite ${\mathrm{Sr}}_{2}M{\mathrm{O}}_{4}$ ($M=4d$ Ru, $4d$ Rh, and $5d$ Ir) using optical spectroscopy and polarization-dependent O $1s$ x-ray absorption spectroscopy. While the ground states of the series of compounds are rather different, their optical conductivity spectra $\ensuremath{\sigma}(\ensuremath{\omega})$ exhibit similar interband transitions, indicative of the common electronic structures of the $4d$ and $5d$ layered oxides. The energy splittings between the two ${e}_{g}$ orbitals, i.e., ${d}_{3{z}^{2}\ensuremath{-}{r}^{2}}$ and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$, are about $2\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, which is much larger than those in the pseudocubic and $3d$ layered perovskite oxides. The electronic properties of the ${\mathrm{Sr}}_{2}M{\mathrm{O}}_{4}$ compounds are discussed in terms of the crystal structure and the extended character of the $4d$ and $5d$ orbitals.
Source: Physical Review B
Authors: S. J. Moon, M. W. Kim, K. W. Kim, Y. S. Lee, J.-Y. Kim, J.-H. Park, B. J. Kim, S.-J. Oh, S. Nakatsuji, Y. Maeno, I. Nagai, S. I. Ikeda, G. Cao, T. W. Noh
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1995445690