Neutron diffraction study on the defect structure of indium-tin-oxide

The defect structure of undoped and Sn-doped In2O3 (ITO) materials was stud ied by preparing powders under different processing environments and perfor ming neutron powder diffraction. The effect of tin doping and oxygen partia l pressure was determined. Structural information was obtained by analyzing neutron powder diffraction data using the Rietveld method. The results inc lude positions of the atoms, their thermal displacements, the fractional oc cupancy of the interstitial oxygen site, and the fractional occupancies of Sn on each of the two nonequivalent cation sites. The tin cations show a st rong preference for the b site versus the d site. The measured electrical p roperties are correlated with the interstitial oxygen populations, which ag ree with the proposed models for reducible (2Sn(In)(.)O(i)")(x) and nonredu cible (2Sn(In)(.)3O(O)O(i)")(x) defect clusters. (C) 2001 American Institut e of Physics.