LAUSR

Abstract This study aims to investigate the 24 d and 8 b site occupancies, valence state, and spin state of Co ions in Co-doped In2O3 prepared by a chemical solution method. The Rietveld analysis of X-ray powder diffraction patterns of the products revealed that Co2+ and Co3+ ions tend to occupy the 24 d and 8 b sites, respectively. X-ray photoelectron spectroscopy analysis indicated that the Co2+ ions are dominant at low-doping region ( x ≤ 0.044 ) and that Co3+ ions appear at high-doping region ( x ≥ 0.052 ). Magnetic susceptibility measurements revealed that the effective Bohr magneton number p e f f is ~3.8 at the low-doping region, consistent with the value for Co2+ in the high-spin ( S = 3 / 2 ) state. The p e f f decreases at the high-doping region, where Co3+ ions appear. These results indicate that the Co3+ ions are in the low-spin ( S = 0 ) state or intermediate-spin ( S = 1 ) state.