Negligible Magnetism in Excellent Structural Quality Cr[subscript x]Ti[subscript 1-x]O[subscript 2] Anatase: Contrast with High-T[subscript C] Ferromagnetism in Structurally Defective Cr[subscript x]Ti[subscript 1-x]O[subscript 2]

Journal Article · Mon Jul 19 04:00:00 EDT 2010 · Phys. Rev. Lett.

DOI:https://doi.org/10.1103/PhysRevLett.95.217203· OSTI ID:1008670

Kaspar, T C; Heald, S M; Wang, C M; Bryan, J D; Droubay, T; Shutthanandan, V; Thevuthasan, S; McCready, D E; Kellock, A J; Gamelin, D R; Chambers, S A ^[1]

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1. UWASH

We reexamine the mechanism of ferromagnetism in doped TiO{sub 2} anatase, using epitaxial Cr:TiO{sub 2} with excellent structural quality as a model system. In contrast to highly oriented but defective Cr:TiO{sub 2} ({approx}0.5{micro}{sub B}/Cr), these structurally superior single crystal films exhibit negligible ferromagnetism. Similar results were obtained for Co:TiO{sub 2}. We show for the first time that charge-compensating oxygen vacancies alone, as predicted by F-center mediated exchange, are not sufficient to activate ferromagnetism. Instead, the onset of ferromagnetism correlates with the presence of structural defects.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1008670
• Journal Information: Phys. Rev. Lett., Journal Name: Phys. Rev. Lett. Journal Issue: (21) ; 11, 2005 Vol. 95; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DEFECTS
FERROMAGNETISM
MAGNETISM
MONOCRYSTALS
OXYGEN
VACANCIES