Defect model and EPR parameters for the tetragonal Yb3+ center in KTaO3 crystal.
The defect model of the tetragonal Yb3+ (at K+ site) center in KTaO3 crystal is suggested, i.e., Yb3+ ion does not occupy the ideal K+ site, but is displaced by an amount DeltaZ along one of 100 axes because of the much smaller ionic radius of Yb3+ compared with that of the replaced K+. Based on the defect model, the EPR parameters (g factors g(parallel), g(perpendicular) and hyperfine structure constants 171A parallel, 171A perpendicular, 173A parallel, 173A perpendicular) are calculated by diagonalizing the 14 x 14 complete energy matrix. The calculated values are in agreement with the observed values and the off-center displacement DeltaZ (approximately 0.2 angstroms) is estimated from the calculations. These results are discussed.
Feng
Wen-Lin
WL
Department of Material Science, Sichuan University, Chengdu 610064, PR China.
Liu
Hong-Gang
HG
Zheng
Wen-Chen
WC
D002412:Cations / Q000737:chemistry; D003460:Crystallization; D004578:Electron Spin Resonance Spectroscopy; D008956:Models, Chemical; D010087:Oxides / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry*; D013635:Tantalum / Q000737:chemistry*; D015018:Ytterbium / Q000737:chemistry*
D002412:Cations; D010087:Oxides; C516825:potassium tantalate oxide; D013635:Tantalum; D015018:Ytterbium; D011188:Potassium