Origin of magnetism and quasiparticles properties in Cr-doped TiO${}_2$

Abstract

Combining LSDA+$U$ and an analysis of superexchange interactions beyond DFT, we describe the magnetic ground states in rutile and anatase Cr-doped TiO${}_2$. In parallel, we correct our LSDA+$U$ ground state through GW corrections ($GW$@LSDA+$U$) that reproduce the position of impurity states and the band gaps in satisfying agreement with experiments. Because of the different topological coordinations of Cr-Cr bonds in the ground states of rutile and anatase, superexchange interactions induce either ferromagnetic or antiferromagnetic couplings of Cr ions. In Cr-doped anatase, this interaction leads to a new mechanism which stabilizes a ferromagnetic ground state, in keeping with experimental evidence, without the need to invoke F-center exchange.

5<pages, 4 figures

References in corpus (4)

• The f-electron challenge: localized and itinerant states in lanthanide oxides united by GW@LDA+U
• Doping effects on the electronic and structural properties of CoO2: An LSDA+U study
• Valence bond crystal in a pyrochlore antiferromagnet with orbital degeneracy
• Valence-Bond Crystal, and Lattice Distortions in a Pyrochlore Antiferromagnet with Orbital Degeneracy

Cited by in corpus (3)

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• Emerging giant resonant exciton induced by Ta-substitution in anatase TiO${}_2$: a tunable correlation effect
• Fingerprints of entangled spin and orbital physics in itinerant ferromagnets via angle resolved $resonant$ photoemission