Theoretical studies of the anisotropic g factors for deoxygenated Y123

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542017
Author(s):  
L. J. Zhang ◽  
S. Y. Wu ◽  
C. C. Ding ◽  
Y. K. Cheng
Keyword(s):  
Experimental Data ◽  
Orbit Coupling ◽  
Theoretical Studies ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Ligand Orbital ◽  
Y123 System ◽  
Good Agreement ◽  
G Factors

The anisotropic [Formula: see text] factors of the deoxygenated YBaCuO (Y123) are theoretically studied using the perturbation formulas of the [Formula: see text] factors for a tetragonally elongated octahedral [Formula: see text] cluster. The ligand orbital and spin-orbit coupling contributions are included from the cluster approach in view of covalency. The calculated [Formula: see text] factors show good agreement with the experimental data. The anisotropy of the [Formula: see text] factors is analyzed by considering the local tetragonal elongation distortion around this five-fold coordinated [Formula: see text] site in the deoxygenated Y123 system.

Studies of the EPR Parameters and Local Structure of Co2+ in ZnO

2011 ◽  
Vol 316-317 ◽  
pp. 1-6 ◽  
Author(s):  
Min Quan Kuang ◽  
Shao Yi Wu ◽  
Bo Tao Song ◽  
Li Li Li
Keyword(s):  
Local Structure ◽  
Orbit Coupling ◽  
Small Displacement ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Distorted Tetrahedron ◽  
Cluster Approach ◽  
Ligand Orbital ◽  
Epr Parameters ◽  
Good Agreement

The EPR parameters and the local structure for Co2+ in ZnO are deduced from the perturbation formulas of these parameters for a 3d7 ion in a trigonally distorted tetrahedron. The ligand orbital and spin-orbit coupling contributions are taken into account uniformly from the cluster approach in view of the covalency of the system. The impurity V3+ is found not to locate exactly on the Zn2+ site but to experience a small displacement of 0.04 Ǻ away from the ligand triangle, along the C3 axis. The theoretical EPR parameters based upon the above impurity displacement are in good agreement with the observed values.

INVESTIGATIONS ON THE LOCAL STRUCTURE AND THE EPR PARAMETERS FORCu2+-DOPEDGaN

2008 ◽  
Vol 22 (18) ◽  
pp. 1739-1747 ◽  
Author(s):  
LI-HUA WEI ◽  
SHAO-YI WU ◽  
ZHI-HONG ZHANG ◽  
HUI WANG ◽  
XUE-FENG WANG
Keyword(s):  
Experimental Data ◽  
Local Structure ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Ligand Orbital ◽  
Epr Parameters ◽  
Structure Constants ◽  
Slight Displacement ◽  
Good Agreement

The local structure and the EPR parameters (g factors and the hyperfine structure constants) for Cu2+in GaN are theoretically studied from the perturbation formulas of these parameters for a 3d9ion in trigonally distorted tetrahedra. In these formulas, the ligand orbital and spin-orbit coupling contributions are taken into account from the cluster approach, in view of the strong covalency effect of the system. Based on the studies, the impurity Cu2+is found not to occupy exactly the host Ga3+site but to suffer a slight displacement (≈ 0.004 Å ) towards the ligand triangle along C3axis due to charge and size mismatching substitution. The theoretical EPR parameters show good agreement with the experimental data. The validity of the impurity displacement is also discussed.

Theoretical Studies of the EPR Parameters for Rh+ in NaCl

2010 ◽  
Vol 303-304 ◽  
pp. 125-129
Author(s):  
Zhi Hong Zhang ◽  
Shao Yi Wu ◽  
Pei Xu ◽  
Li Li Li
Keyword(s):  
Structure Constant ◽  
Theoretical Studies ◽  
Spin Orbit Coupling ◽  
Cluster Approach ◽  
Paramagnetic Resonance ◽  
Hyperfine Structure Constant ◽  
Ligand Orbital ◽  
Epr Parameters ◽  
Electron Paramagnetic ◽  
Good Agreement

The electron paramagnetic resonance (EPR) parameters g factor and the hyperfine structure constant A factor for the substitutional Rh+ in NaCl are theoretically studied from the perturbation formulas of these parameters for a 4d8 ion in cubic octahedra. In these formulas, the ligand orbital and spin-orbit coupling contributions which were normally omitted in the previous studies are taken into account using the cluster approach. The calculated g and A factors are in good agreement with the experimental data. The ligand contributions to the EPR parameters are somewhat important and should be considered in the analysis of the EPR spectra for a 4d8 ion in chlorides. The local structure of this center is also discussed.

Investigations Of The G Factors Of Fe+ In Mgo And Cao

2005 ◽  
Vol 60 (5) ◽  
pp. 366-368 ◽  
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong
Keyword(s):  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Octahedral Symmetry ◽  
Cluster Approach ◽  
Coupling Interaction ◽  
Perturbation Formula ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
G Factors

The g factors of Fe+ in MgO and CaO are theoretically investigated by the perturbation formula of the g factor of a 3d7 ion in cubic octahedral symmetry based on the cluster approach. By considering the partial quenching of the spin-orbit coupling interaction and the effective Land´e factor due to the dynamic Jahn-Teller effect (DJTE), the experimental g factors of the studied systems are reasonably interpreted. It can be suggested that the small g factors of the Fe+ centers in MgO and CaO can be likely attributed to the DJTE, rather than the covalency effect within the scheme of the static crystalfield model.

Investigations of the Isotropic G Factors for the Cubic Fe+ Centers in LiF and NaF

2013 ◽  
Vol 634-638 ◽  
pp. 91-94
Author(s):  
Xian Fen Hu ◽  
Shao Yi Wu ◽  
Min Quan Kuang ◽  
Bo Tao Song
Keyword(s):  
Crystal Field ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cubic Crystal ◽  
G Factor ◽  
Perturbation Formula ◽  
Ligand Orbital ◽  
G Factors

The g factors for the cubic Fe+centers in LiF and NaF are theoretically investigated from the perturbation formula of the g factor for an octahedral 3d7cluster including the contributions from the ligand orbital and spin-orbit coupling interactions. The increasing order of the g factor (i.e., LiF < NaF) can be ascribed to the decrease in covalency and the strength of cubic crystal-field of the systems. The validity of the results is discussed.

THEORETICAL STUDIES ON THE GYROMAGNETIC FACTORS FORFe3+INZnX(X=O,S,Se,Te)

2010 ◽  
Vol 24 (17) ◽  
pp. 1891-1898 ◽  
Author(s):  
XUE-FENG WANG ◽  
SHAO-YI WU ◽  
PEI XU ◽  
LI-LI LI
Keyword(s):  
Experimental Data ◽  
Charge Transfer ◽  
Crystal Field ◽  
Reasonable Agreement ◽  
Model Parameters ◽  
Theoretical Studies ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Perturbation Formula

The gyromagnetic factors for Fe3+in ZnX ( X = O , S , Se , Te ) are theoretically studied from the perturbation formula of the g-factor for a 3d5ion in tetrahedra based on inclusion of both the crystal-field and the charge-transfer contributions. The related model parameters in the calculations are determined from the cluster approach in a uniform way. The g-shift Δg (= g-gs, where gs≈ 2.0023 is the spin-only value) from the charge-transfer contributions is opposite (positive) in sign and much larger in magnitude as compared with that from the crystal-field ones. The importance of the charge-transfer contributions increases rapidly with increasing the covalency and the spin-orbit coupling coefficient of the ligand and thus exhibits the order of O2-< S2-< Se2-< Te2-. The calculated g-factors by considering both the crystal-field and charge-transfer contributions show reasonable agreement with the experimental data for all the Fe3+centers in ZnX .

Theoretical Studies of the g Factors for Co2+ in MgO and CaO Crystals

2001 ◽  
Vol 56 (3-4) ◽  
pp. 249-252 ◽  
Author(s):  
Shao-Yi Wu ◽  
Wen-Chen Zheng
Keyword(s):  
Configuration Interaction ◽  
Optical Spectra ◽  
Theoretical Studies ◽  
Cluster Approach ◽  
Experimental Values ◽  
Good Agreement ◽  
G Factors

Abstract This paper presents a cluster approach to the calculation of the g factors for 3d7 ions in cubic oc­ tahedral crystals, in which the parameters related to the configuration interaction and the covalency reduction effects are obtained from optical spectra of the studied crystals, and so no adjustable parameters are applied. From the approach, the g factors for MgO:Co2+ and CaO:Co2+ are cal­culated. The calculated results show good agreement with the observed values. The experimental values of g 4.333 for CaO:Co2+ are also explained.

Theoretical Studies of the EPR g Factors and the Hyperfine Structure Constants of Cr3+ in MgS and SrS

2003 ◽  
Vol 58 (9-10) ◽  
pp. 503-506
Author(s):  
Shao-Yi Wu ◽  
Xiu-Ying Gao ◽  
Wei-Zi Yan
Keyword(s):  
Hyperfine Structure ◽  
Coupling Coefficient ◽  
Structure Constant ◽  
Theoretical Studies ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Hyperfine Structure Constant ◽  
Structure Constants ◽  
G Factors

The EPR g factors and the hyperfine structure constant A factors for Cr3+ in MgS and SrS are theoretically studied by using the two-spin-orbit (S.O.)-coupling-coefficient formulas for a 3d3 ion in octahedra based on the cluster approach. In these formulas, both the contributions due to the S.O. coupling coefficient of the central 3d3 ion and that of ligands are taken into account. Based on these studies, the g and A factors of Cr3+ in both MgS and SrS are satisfactorily explained. The results are discussed.

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