ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
One of the most controversial topics in condensed matter physics concerns the nature of the electronic structure of transition metal oxides. Unpolarized band structure calculations predict metallic ground states for these oxides, whereas experimentally they are insulating. This led to the development of the Mott insulator picture for these materials fifty years ago. Later, though, Slater's group showed that by taking into account spin polarization, one could produce insulating gaps from band theory for MnO and NiO. The gaps are too small, the size of the gap actually being determined by the Mott-Hubbard U, but this led to a hope that on symmetry grounds one could also obtain gaps for the other two metal oxides, FeO and CoO. In these two cases, there is an unquenched orbital moment, which might be important for this purpose. Recently, a theory has been developed by Erickson, Brooks, and Johansson for including an orbital polarization correction to local spin density theory.1 The author in turn showed that such a correction can lead to insulating gaps for CoO and FeO.2 A discussion of these results, including the calculated sizes of the moments, as well as related work on insulating mixed valent TmSe, will be presented in this paper.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.347835
