Studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Fe5+ center in SrTiO3 crystals using a two-mechanism model

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	Studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Fe5+ center in SrTiO3 crystals using a two-mechanism model
	W. C. Zheng; X. X. Wu; W. Fang
	2007
发表期刊	Journal of Physics-Condensed Matter
ISSN	0953-8984
卷号	19 期号:45
摘要	The high order perturbation formulas for spin-Hamiltonian (SH) parameters ( g factors g parallel to, g perpendicular to and zero-field splitting D) for 3d(3) ions in tetragonal symmetry are established using a cluster approach. In these formulas, not only is the contribution to the SH parameters from the crystal-field (CF) mechanism included, but so also is that from the charge-transfer (CT) mechanism ( which is neglected in the widely used CF theory). From these formulas, the g shifts Delta g parallel to (= g parallel to - g(e), where g(e) approximate to 2.0023, the value for the free electron),Delta g(perpendicular to). (= g perpendicular to- g(e)) and the zero-field splitting D for the tetragonal Fe5+ center in SrTiO3 crystal are calculated. The results ( in particular, the positive g shifts, which cannot be explained on the basis of the CF mechanism) are in good agreement with the observed values. The calculation results show that (i) the sign of Delta g(i)(CT) ( i = parallel to or perpendicular to) due to the CT mechanism is opposite to that of Delta g(i)(CF) due to the CF mechanism, but the sign of D-CT is the same as that of D-CF and (ii) the ratio \| Q(CT)/ Q(CF)\| (which represents the relative importance of the CT mechanism) takes values of about 143%, 143% and 114% for Q = Delta g parallel to, Delta g perpendicular to and D, respectively. This suggests that the positive g shifts are due mainly to the contribution of the CT mechanism; therefore for the high valence state 3d(n) ions in crystals, the contribution to SH parameters from the CT mechanism should be taken into account. The defect structure of the Fe5+ center in SrTiO3 crystal is also obtained from the calculations. The result is consistent with the expectations based on charge compensation and electrostatic interaction.
部门归属	sichuan univ, dept mat sci, chengdu 610064, peoples r china. civil aviat flying inst china, dept phys, guanghan 618307, 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;zhengwc1@163.com
关键词	Atomic Screening Constants Scf Functions Doped Srtio3 Impurities Electrons Fields Terms Cr3++ Epr
URL	查看原文
WOS记录号	WOS:000250688700035
引用统计	被引频次：8[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34094
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	W. C. Zheng,X. X. Wu,W. Fang. Studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Fe5+ center in SrTiO3 crystals using a two-mechanism model[J]. Journal of Physics-Condensed Matter,2007,19(45).
APA	W. C. Zheng,X. X. Wu,&W. Fang.(2007).Studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Fe5+ center in SrTiO3 crystals using a two-mechanism model.Journal of Physics-Condensed Matter,19(45).
MLA	W. C. Zheng,et al."Studies of the spin-Hamiltonian parameters and defect structure for the tetragonal Fe5+ center in SrTiO3 crystals using a two-mechanism model".Journal of Physics-Condensed Matter 19.45(2007).