Theoretical studies of the local structure for the trigonal Ti(3+) center in LiF crystal.
The local structure of the trigonal Ti(3+) center in LiF crystal is theoretically investigated by using the perturbation formulas of the anisotropic g factors and g(//) and g(/_) for a 3d(1) ion in trigonally distorted octahedra based on the cluster approach. From the studies on the basis of various possible structure models, the local structure of the trigonal Ti(3+) center may be characterized as [TiF(3)O(3)](6-) cluster (or model I). In this model, the impurity Ti(3+) is expected to substitute for the host Li(+) ion and shift away from its regular lattice site along the [111] (or C(3)) axis by about 0.19 A due to the strong electrostatic attraction of the O(2-) triangle replacing the original F(-) triangle. The magnitude of the above displacement obtained in this work is comparable with that ( approximately 0.2-0.3A) given by ENDOR experiment. Moreover, the cubic field parameter Dq (approximately 1497 cm(-1)) based on the above structure model is also in agreement with that (approximately 1500 cm(-1)) obtained from the experimental optical spectra of the studied system. The theoretical investigations of the local structure in this work may be useful to understand optical properties of Ti-doped LiF.
Wu
Shao-Yi
SY
Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, PR China.
Gao
Xiu-Ying
XY
Yan
Wei-Zi
WZ
Wei
Wang-He
WH
D004578:Electron Spin Resonance Spectroscopy; D005459:Fluorides / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D018020:Lithium Compounds; C027651:lithium fluoride; D014025:Titanium; D005459:Fluorides