Electronic structure ofPrCoO3and its temperature evolution

Abstract

We investigate the detailed electronic structure of $\mathrm{Pr}\mathrm{Co}{\mathrm{O}}_{3}$ and its temperature evolution by using high-resolution photoemission spectroscopy and ab initio band structure calculations. We observe that, in addition to the correlation effect, spin-orbit interaction plays an important role in determining the electronic properties of this system. $\mathrm{Pr}\phantom{\rule{0.2em}{0ex}}4f$ states are found to be strongly hybridized with the $\mathrm{O}\phantom{\rule{0.2em}{0ex}}2p$ and $\mathrm{Co}\phantom{\rule{0.2em}{0ex}}3d$ valence electronic states and appear in the vicinity of the Fermi level. The calculated results corresponding to the intermediate spin state of Co provide a good representation of the experimental spectra at $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The decrease in temperature from $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ leads to a gradual enhancement of the $\mathrm{O}\phantom{\rule{0.2em}{0ex}}2p$ character in the bonding features, indicating the signature of an enhancement of the low spin state contributions at lower temperatures. The temperature evolution of the shift of the valence band edge is found to be consistent with the transport data.