From the perturbation formulas for the EPR g factors g(parallel to) and g(perpendicular to) of a 3d(7) ion in tetragonal octahedral crystal field based on a cluster approach, the geometrical microstructures of tetragonal Co2+-V-O centers in KNbO3 and KTaO3 crystals are obtained by fitting the calculated g(parallel to) and g(perpendicular to) to the observed values. It is found that the Co2+ ion in Co2+-V-O centers is displaced away from the oxygen vacancy V-O by 0.3 Angstrom in KNbO3 and by 0.29 Angstrom in KTAO(3). These results are comparable with those of Fe3+-V-O centers in ABO(3) perovskite-type crystals obtained from both the shell-model simulations and the embedded-cluster calculations, and from theoretical studies of EPR data. The experimental values of g(parallel to) and g(perpendicular to) for the tetragonal Co2+-V-O centers in both crystals are also explained reasonably.
部门归属
sichuan univ, dept mat sci, chengdu 610064, peoples r china. chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china.;zheng, wc (reprint author), sichuan univ, dept mat sci, chengdu 610064, peoples r china
W. C. Zheng,S. Y. Wu. The studies of geometrical microstructure of tetragonal Co2+-V-O centers in KNbO3 and KTaO3 crystals from EPR data[J]. Zeitschrift Fur Naturforschung Section a-a Journal of Physical Sciences,2002,57(12):925-928.
APA
W. C. Zheng,&S. Y. Wu.(2002).The studies of geometrical microstructure of tetragonal Co2+-V-O centers in KNbO3 and KTaO3 crystals from EPR data.Zeitschrift Fur Naturforschung Section a-a Journal of Physical Sciences,57(12),925-928.
MLA
W. C. Zheng,et al."The studies of geometrical microstructure of tetragonal Co2+-V-O centers in KNbO3 and KTaO3 crystals from EPR data".Zeitschrift Fur Naturforschung Section a-a Journal of Physical Sciences 57.12(2002):925-928.
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