Studies of EPR g factors for tetragonal and rhombic Cr5+centers in ferroelectric PbTiO3

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	Studies of EPR g factors for tetragonal and rhombic Cr5+centers in ferroelectric PbTiO3
	Y. G. Yang; Y. Mei; P. Su; W. C. Zheng
	2012
发表期刊	Crystal Research and Technology
ISSN	0232-1300
卷号	47 期号:1 页码:39-44
摘要	The anisotropic g factors (gx, gy, gz) at low temperature and the motionally averaged isotropic g factor at high temperature for two Cr5+ centers, the tetragonal t-Cr5+ center and the rhombic O-Cr5+ center, in ferroelectric PbTiO3 are calculated from the high-order perturbation formulas based on a two-mechanism model. In the model, the contributions to g factors from both the crystal-field (CF) mechanism concerning the CF excited states and the charge-transfer (CT) mechanism (which is neglected in CF theory) concerning the CT excited states are contained. The calculated results are in reasonable agreement with the experimental values. From the calculations, the defect models of t-Cr5+ center (which is attributed to Cr5+ in the tetragonally-compressed octahedron caused by Jahn-Teller effect rather than in the tetragonally-elongated octahedron in the host PbTiO3) and O-Cr5+ center (which is due to the t-Cr5+ center perturbated by the electrical polarization perpendicular to the C4 axis) are confirmed, and the defect structure of t-Cr5+ center is obtained. It is found that in the precise calculations of g factors for the high valence state d1 ions in crystals, both the contributions due to CF and CT mechanisms should be taken into account. (c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
部门归属	[yang yu-guang; su ping; zheng wen-chen] sichuan univ, dept mat sci, chengdu 610064, peoples r china. [mei yang] mianyang normal univ, sch phys & elect engn, mianyang 621000, peoples r china. [zheng wen-chen] 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	Epr Spectrum Defect Model Crystal Field Theory Pbtio3 Electron-paramagnetic-resonance Atomic Screening Constants Temperature-dependence Superposition Model Gyromagnetic Factor Crystal-field Scf Functions Ions Impurities Complexes
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/60402
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. G. Yang,Y. Mei,P. Su,et al. Studies of EPR g factors for tetragonal and rhombic Cr5+centers in ferroelectric PbTiO3[J]. Crystal Research and Technology,2012,47(1):39-44.
APA	Y. G. Yang,Y. Mei,P. Su,&W. C. Zheng.(2012).Studies of EPR g factors for tetragonal and rhombic Cr5+centers in ferroelectric PbTiO3.Crystal Research and Technology,47(1),39-44.
MLA	Y. G. Yang,et al."Studies of EPR g factors for tetragonal and rhombic Cr5+centers in ferroelectric PbTiO3".Crystal Research and Technology 47.1(2012):39-44.