Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase
The quest for diluted magnetic semiconductors (DMS) which retain their magnetism at and above room temperature is spanning several classes of materials. Such materials are critically important in the development of spintronics as spin injectors for semiconductor heterostructures that can operate without cryogenic cooling. Group IV, III-V, and II-VI DMS materials typically exhibit Curie temperatures (Tc) well below ambient due to weak interaction of the magnetic impurities. Calculations based on the Zener model of magnetism suggest that the strongest interaction is that mediated by holes, and experimental studies carried out to date have borne out this prediciton. One notable exception is that of Mn-doped GaN, which grows n-type by gas-source molecular beam epitaxy under certain conditions, and appears to be ferromagnetic at room temperature. In addition, it has recently been shown that at least one oxide semiconductor - Co-doped TiO₂ anatase or CoxTi₁-xO₂-x - is ferromagnetic well above room temperature when doped n-type by oxygen vacancies for x < ~0.1, but the mechanism of magnetism remains unknown.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 15003791
- Report Number(s):
- PNNL-SA-37018; PRBMDO; 6292; TRN: US201015%%123
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, 67(10):22-25, art. no. 100401, Vol. 67, Issue 10; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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