Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1234617 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2008 | 5 Pages |
Abstract
The defect structures and the g factors for the two orthorhombic Ti3+ centers (A and B) in CaYAlO4 are theoretically investigated from the perturbation formulas of the g factors gξ, gη and gξ for a 3d1 ion in orthorhombically distorted octahedra. The centers may be attributed to Ti3+ locating on the Al3+ site associated with one nearest-neighbouring oxygen vacancy (VO) along the z (or c) axis and additional next-nearest-neighbouring Ti4+ replacing the host Al3+ (TiAl, i.e., center A) or Al3+ vacancy (VAl, i.e., center B) perpendicular to the c axis, respectively. Due to the electrostatic interactions arising from the local charge mismatch, the central Ti3+ undergoes a large displacement ÎZ away from the VO in the c axis, while the ligand O2â intervening in the Ti3+ and TiAl (or VAl) suffers a small outward (or inward) shift ÎX in the corresponding c plane related to the center of oxygen octahedron. The theoretical g factors for both centers based on the above displacements are in reasonable agreement with the observed values.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Shao-Yi Wu, Ji-Zi Lin, Qiang Fu, Hui-Ning Dong,