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Local structures and roles of Fe 3+ and Cr 3+ in p‐type semiconductor CuAlO 2
Author(s) -
Huang Dan,
Lin Jinru,
Nilges Mark J.,
Pan Yuanming
Publication year - 2012
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201147466
Subject(s) - electron paramagnetic resonance , chemistry , semiconductor , ion , impurity , crystallography , hamiltonian (control theory) , superposition principle , center (category theory) , spectroscopy , atomic physics , condensed matter physics , molecular physics , nuclear magnetic resonance , physics , quantum mechanics , mathematical optimization , mathematics , organic chemistry
Single crystals of the p‐type semiconductor CuAlO 2 , synthesized from the CuO flux method, have been investigated by electron paramagnetic resonance (EPR) spectroscopy at temperatures from 3.5 to 294 K. EPR spectra reveal an axial Cr 3+ center and an axial Fe 3+ center, presumably arising from impurities in the starting materials. The Cr 3+ center at 294 K is characterized by g = 1.979(1) and D = − 7803(3) × 10 −4 cm −1 . The Fe 3+ center at 294 K has g // = 1.9942(1), g ⟂ = 1.9964(1), D = 261.9(3) × 10 −4 cm −1 , $B_{4}^{0} = 4.533(3) \times 10^{- 4} \,{\rm cm}^{- 1} $ , and $B_{4}^{3} = 104.23(3) \times 10^{- 4} \,{\rm cm}^{- 1} $ . These spin‐Hamiltonian parameters, evaluated by superposition model analyses and periodic density functional theory (DFT) calculations, suggest that both Cr 3+ and Fe 3+ occupy the Al 3+ site but the latter involves distortion related to perturbation from a substitutional Cu + ion at the nearest Al site. This difference in the local structure between Fe 3+ and Cr 3+ explains their contrasting effects on the p‐type conductivity in CuAlO 2 .