Origin of magnetism in cobalt-doped indium tin oxide thin films

DOI: 10.1103/PhysRevB.82.144429

Authors: A. M. H. R. Hakimi (University of Cambridge) , F. Schoofs (University of Cambridge) , R. Bali (Max Planck Institute of Microstructure Physics) , N. A. Stelmashenko (University of Cambridge) , M. G. Blamire (University of Cambridge) , S. Langridge (Science and Technology Facilities Council) , S. A. Cavill (Diamond Light Source) , G. Van Der Laan (Diamond Light Source) , S. S. Dhesi (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review B , VOL 82 (14) , PAGES 144429

State: Published (Approved)
Published: October 2010

Abstract: We report an x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) study of a 5.4 at. % Co-doped indium tin oxide (ITO) thin film shown to exhibit ferromagnetism beyond room temperature. The XAS spectra at the Co L2,3 edge reveal pronounced multiplet features characteristic of divalent octahedrally coordinated Co2+ ions. The results suggest that the Co2+ ions are nonmetallic and substitute for the In site in ITO. Magnetic field and temperature-dependent XMCD spectra imply that the Co2+ ions give a paramagnetic contribution to the overall ferromagnetic response both at the near-surface region and throughout the bulk of the films. No magnetic polarization was detected at the In M2,3 or Sn M2,3 edges. We therefore presume that the ferromagnetism observed is a result of the sp-d exchange interaction between the sp band of the host ITO and that of the localized d electrons of the transition-metal Co dopants.

Diamond Keywords: Ferromagnetism

Subject Areas: Physics, Materials


Instruments: I06-Nanoscience (XPEEM)

Added On: 26/10/2010 08:16

Discipline Tags:

Surfaces Quantum Materials Physics Magnetism Materials Science interfaces and thin films

Technical Tags:

Spectroscopy Circular Dichroism (CD) X-ray Absorption Spectroscopy (XAS) X-ray Magnetic Circular Dichroism (XMCD)