First-principles calculations and re-analysis of optical spectra and electron paramagnetic resonance parameters for Yb3+ in YAl3（BO3）4 crystal
来源期刊：JOURNAL OF RARE EARTHS2017年第3期
论文作者：李邦兴 梁致辉 杨友源
文章页码：254 - 258
摘 要：In this paper,the energy levels of Yb3+ ions in yttrium aluminum borate（YAB） crystal were calculated from a first-principles approach with an optimized defect structure obtained from the WIEN2 k package and a traditional fitting method using a more reliable computer package.The calculated results were then compared with those obtained from a re-calculation using the values of parameters given by some previous researchers.Three types of likely mistakes in the previous researcher’s paper,namely over fitting,incorrect use of irreducible representation,and errors in the calculations for the EPR parameters were clearly identified and effectively rectified in this paper.The electron paramagnetic resonance（EPR） parameters,which included g factors like g（//） and g⊥ and hyperfine structure constants A// and A⊥,were also calculated through the perturbation method and compared with some observed values available in literature.There was reasonable agreement found with the experimental values which lay between the values obtained from the first-principles calculation(g//=4.000 and g⊥=1.391;A//=1032 and A⊥=360 in 10-4 cm-1 for 171Yb3+) and those from the fitting approach(g//=3.612 and g⊥=1.702;A//=867 and A⊥=470 in 10-4 cm-1 for 171Yb3+).
李邦兴，梁致辉，杨友源
Department of Science and Environmental Studies,The Education University of Hong Kong
摘 要：In this paper,the energy levels of Yb3+ ions in yttrium aluminum borate（YAB） crystal were calculated from a first-principles approach with an optimized defect structure obtained from the WIEN2 k package and a traditional fitting method using a more reliable computer package.The calculated results were then compared with those obtained from a re-calculation using the values of parameters given by some previous researchers.Three types of likely mistakes in the previous researcher’s paper,namely over fitting,incorrect use of irreducible representation,and errors in the calculations for the EPR parameters were clearly identified and effectively rectified in this paper.The electron paramagnetic resonance（EPR） parameters,which included g factors like g（//） and g⊥ and hyperfine structure constants A// and A⊥,were also calculated through the perturbation method and compared with some observed values available in literature.There was reasonable agreement found with the experimental values which lay between the values obtained from the first-principles calculation(g//=4.000 and g⊥=1.391;A//=1032 and A⊥=360 in 10-4 cm-1 for 171Yb3+) and those from the fitting approach(g//=3.612 and g⊥=1.702;A//=867 and A⊥=470 in 10-4 cm-1 for 171Yb3+).
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