Abstract
We study the electronic and magnetic structure of -hematite and -hematite doped with Ti using density-functional theory. We use both the local spin-density approximation (LSDA) and the local spin-density approximation with Coulomb correlation approximations. We find that as the value of the parameter U is increased, -hematite(Ti) changes from a magnetic half metal with a single relatively delocalized d electron per Ti to an insulator which has the electron localized on a particular Fe site neighboring the Ti impurity. In contrast to Ti-doped -hematite, LSDA and LSDA+U are in qualitative agreement for the undoped system, although predicts values of the structural parameters, band gap, and magnetic moments on the Fe sites which are closer to experimental estimates. In general, appears to be better suited for this type of material.
- Received 30 October 2003
DOI:https://doi.org/10.1103/PhysRevB.69.174429
©2004 American Physical Society