Authors
Aswini K. Pradhan, Center for Materials Research, Norfolk State UniversityFollow
D. Hunter, Center for Materials Research, Norfolk State University, Norfolk, Virginia
J.B. Dadson, Center for Materials Research, Norfolk State University, Norfolk, Virginia
T.M. Williams, Center for Materials Research, Norfolk State University, Norfolk, Virginia
Kai Zhang, Center for Materials Research, Norfolk State University, Norfolk, Virginia
K. Lord, Center for Materials Research, Norfolk State University, Norfolk, Virginia
B. Lasley, Center for Materials Research, Norfolk State University, Norfolk, Virginia
Rakhim R. Rakhimov, Center for Materials Research, Norfolk State UniversityFollow
Jun Zhang, University of Nebraska - LincolnFollow
David J. Sellmyer, University of Nebraska-LincolnFollow
U.N. Roy, Department of Physics, Fisk University, Nashville, Tennessee
Y. Cui, Department of Physics, Fisk University, Nashville, Tennessee
A. Burger, Department of Physics, Fisk University, Nashville, Tennessee
C. Hopkins, College of William and Mary, Applied Research Center, Newport News, Virgina
N. Pearson, College of William and Mary, Applied Research Center, Newport News, Virgina
A.L. Wilkerson, College of William and Mary, Applied Research Center, Newport News, Virgina
Date of this Version
5-30-2005
Abstract
We report on the observation of remarkable room-temperature ferromagnetism in nanocrystalline epitaxial Co:TiO2 films grown on sapphire (0001) substrates by a pulsed-laser deposition technique using high-density targets. The films were characterized by x-ray measurements, atomic force microscopy, micro-Raman, electron-paramagnetic resonance, and magnetization studies. The films exhibit three-dimensional islandlike growth that contains nanocrystalline particles. Our experimental results suggest that the remarkable ferromagnetism in Co:TiO2 films is controlled either by the interstitial Co2+ ions or small clusters, which are mainly present at the interface and on the surface of the films. Our work clearly indicates that Co interstitials and nanoclusters cause room-temperature ferromagnetism in Co-doped TiO2.
Comments
Published by American Institute of Physics. Appl. Phys. Lett. 86, 222503 (2005). ©2005 American Institute of Physics. Permission to use. http://apl.aip.org/jap/.