skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase

Abstract

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.

Authors:
; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
15003791
Report Number(s):
PNNL-SA-37018
Journal ID: ISSN 0163-1829; PRBMDO; 6292; TRN: US201015%%123
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics, 67(10):22-25, art. no. 100401
Additional Journal Information:
Journal Volume: 67; Journal Issue: 10; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CRYOGENICS; CURIE POINT; IMPURITIES; MAGNETIC SEMICONDUCTORS; MAGNETISM; MOLECULAR BEAM EPITAXY; OXIDES; OXYGEN; SPIN; TITANIUM OXIDES; VACANCIES; WEAK INTERACTIONS; DMS; spintronics; Tc; magnetism; Environmental Molecular Sciences Laboratory

Citation Formats

Chambers, Scott A., Heald, Steve M., and Droubay, Timothy C. Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase. United States: N. p., 2003. Web. doi:10.1103/PhysRevB.67.100401.
Chambers, Scott A., Heald, Steve M., & Droubay, Timothy C. Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase. United States. https://doi.org/10.1103/PhysRevB.67.100401
Chambers, Scott A., Heald, Steve M., and Droubay, Timothy C. Sat . "Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase". United States. https://doi.org/10.1103/PhysRevB.67.100401.
@article{osti_15003791,
title = {Local Co Structure in Epitaxial Cox Ti₁-xO₂-x Anatase},
author = {Chambers, Scott A. and Heald, Steve M. and Droubay, Timothy C.},
abstractNote = {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.},
doi = {10.1103/PhysRevB.67.100401},
url = {https://www.osti.gov/biblio/15003791}, journal = {Physical Review. B, Condensed Matter and Materials Physics, 67(10):22-25, art. no. 100401},
issn = {0163-1829},
number = 10,
volume = 67,
place = {United States},
year = {2003},
month = {3}
}