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.

Studies of the g Factors and the Hyperfine Structure Constants for the Octahedral Interstitial Mn2+ and Cr+ Impurities in Silicon

2013 ◽  
Vol 68 (5) ◽  
pp. 337-342 ◽  
Author(s):  
Bo-Tao Song ◽  
Shao-Yi Wu ◽  
Zhi-Hong Zhang ◽  
Li-Li Li
Keyword(s):  
Experimental Data ◽  
Charge Transfer ◽  
Hyperfine Structure ◽  
Crystal Field ◽  
Structure Constant ◽  
Cluster Approach ◽  
Hyperfine Structure Constant ◽  
Structure Constants ◽  
Good Agreement ◽  
G Factors

The g factors and the hyperfine structure constants for the octahedral interstitial Mn2+ and Cr+ impurities in silicon are theoretically studied using the perturbation formulas of these parameters for an octahedral 3d5 cluster. In the calculations, both the crystal-field and charge transfer contributions are taken into account in a uniform way, and the related molecular orbital coefficients are quantitatively determined from the cluster approach. The theoretical g factors and the hyperfine structure constants are in good agreement with the experimental data. The charge transfer contribution to the g-shift (≈g-gs, where gs ≈ 2:0023 is the spin only value) is opposite (positive) in sign and about 51% - 116% in magnitude as compared with the crystal-field one for Mn2+ and Cr+, respectively. Nevertheless, the charge transfer contribution to the hyperfine structure constant has the same sign and about 12% - 19% that of the crystal-field one. Importance of the charge transfer contribution shows the order Cr+ < Mn2+ due to increase of the impurity valence state in the same host, especially for the g factor.

Investigation of the Spin Hamiltonian Parameters of a Tetragonal VO2+ Center in (NH4)2SbCl5

2006 ◽  
Vol 61 (10-11) ◽  
pp. 583-587 ◽  
Author(s):  
Ji-Zi Lin ◽  
Shao-Yi Wu ◽  
Qiang Fu ◽  
Guang-Duo Lu
Keyword(s):  
Experimental Data ◽  
Hyperfine Structure ◽  
Coupling Coefficient ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Spin Hamiltonian ◽  
Cluster Approach ◽  
Crystal Fields ◽  
Structure Constants ◽  
Hamiltonian Parameters

The spin Hamiltonian parameters g‖ and g⊥ and the hyperfine structure constants A‖ and A⊥ of a tetragonal VO2+ center in (NH4)2SbCl5 are investigated, using the perturbation formulas for a 3d1 ion in tetragonally compressed octahedra. In these formulas, the contributions to the spin Hamiltonian parameters from the s- and p-orbitals as well as the spin-orbit coupling coefficient of the Cl− ligand are taken into account, based on the cluster approach. According to these studies, compression of the ligand octahedra results from the strong axial crystal-fields due to the short V4+-O2− bond in the [VOCl4]2− cluster. The obtained spin Hamiltonian parameters agree well with the experimental data and need fewer adjustable parameters than the previous studies. The covalency of the studied system is also discussed.

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.

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.

Studies on the g Factor and Hyperfine Structure Constant for Ir4+ in CdO

2013 ◽  
Vol 344 ◽  
pp. 85-88
Author(s):  
Xian Fen Hu ◽  
Shao Yi Wu ◽  
Chang Chun Ding
Keyword(s):  
Experimental Data ◽  
Hyperfine Structure ◽  
Structure Constant ◽  
Cluster Approach ◽  
G Factor ◽  
Hyperfine Structure Constant ◽  
High Impurity ◽  
Ligand Orbital ◽  
Account Due ◽  
Good Agreement

The isotropic g factor and hyperfine structure constant for Ir4+in CdO are theoretically studied from the perturbation formulas of these parameters for an octahedral 5d5cluster based on the cluster approach. The calculated results show good agreement with the experimental data. The ligand orbital contributions should be taken into account due to significant covalency of the system with high impurity valence state even in the oxide.

INVESTIGATIONS ON THE SPIN HAMILTONIAN PARAMETERS FOR Nd3+ IN ThGeO4

2007 ◽  
Vol 21 (02) ◽  
pp. 191-197
Author(s):  
SHAO-YI WU ◽  
HUI-NING DONG
Keyword(s):  
Hyperfine Structure ◽  
Second Order ◽  
Experimental Results ◽  
Order Perturbation ◽  
Tetragonal Symmetry ◽  
Theoretical Studies ◽  
Spin Hamiltonian ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
G Factors

The spin Hamiltonian parameters, g factors g‖ and g⊥, for Nd 3+ in ThGeO 4 are theoretically investigated from the perturbation formulas of the g factors for a 4f3 ion in tetragonal symmetry. In these formulas, the contributions to the g factors from the second-order perturbation terms and the admixture of various states are taken into account. It is found that the calculated g factors of this work are smaller than the experimental results, but close to those in the previous theoretical studies by Gutowska et al. Moreover, the calculated hyperfine structure constants A‖ and A⊥ as well as the energies of the 4I9/2 Stark levels in this work are also consistent with those in the previous investigations. The discrepancy between theoretical and experimental g factors is discussed.

Theoretical Investigations of the Spin Hamiltonian Parameters and the Local Structure of a Trigonal Co2+ Center in Bi4Ge3O12

2004 ◽  
Vol 59 (9) ◽  
pp. 563-567
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dongb
Keyword(s):  
Hyperfine Structure ◽  
Local Structure ◽  
Reasonable Agreement ◽  
Spin Hamiltonian ◽  
Cluster Approach ◽  
Trigonal Symmetry ◽  
Theoretical Investigations ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
G Factors

The spin Hamiltonian parameters anisotropic g factors g||, g⊥ and hyperfine structure constants A||and A⊥, as well as the local structure of the trigonal Co2+ center in Bi4Ge3O12 (BGO) are theoreticallyinvestigated by the perturbation formulas of the spin Hamiltonian parameters for a 3d7 ion intrigonal symmetry, based on the cluster approach. It is found that the impurity Co2+ substituting thehost Bi3+ undergoes an off-center displacement ΔZ(≈ −0.132 Å ) away from the center of the oxygenoctahedron along the C3 axis. The spin Hamiltonian parameters based on the above displacementshow reasonable agreement with the observed values. The results are discussed.

Explanation of the g-factors and Hyperfine Structure Constants of Co2+ in Tetragonal K2ZnF4

2000 ◽  
Vol 55 (5) ◽  
pp. 539-544 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Shao-Yi Wu
Keyword(s):  
Hyperfine Structure ◽  
Configuration Interaction ◽  
Structural Parameters ◽  
Cluster Approach ◽  
Epr Parameters ◽  
Structure Constants ◽  
The Relationship ◽  
Good Agreement ◽  
G Factors

Abstract The formulas of the g-factors gII , g┴ and the hyperfine structure constants AII.A┴ for 3d7 ions in tetragonal octahedral crystals are established from a cluster approach. Differing from previous formulas, in these formulas the role of configuration interaction (CI)-and covalency (CO)-effects is considered, and the parameters related to both effects are obtained from the optical spectra and the structural parameters of the studied crystal. From these formulas, the EPR parameters gi and Ai for K2 ZnF4 :Co2+ are calculated. The results show good agreement with the observed values. The contributions to the EPR parameters gi and Ai, from the CI and CO effects, and the relationship between the sign of Δg(=g┴ - gII) and the tetragonal distortion (elongated or compressed) of the ligand octahedron are discussed

Investigations on the Hyperfine and Superhyperfine Interaction Parameters for Cs2GeF6:Mn4+

2005 ◽  
Vol 60 (8-9) ◽  
pp. 611-614 ◽  
Author(s):  
Shao-Yi Wu ◽  
Xiu-Ying Gao ◽  
Hui-Ning Dong
Keyword(s):  
Hyperfine Structure ◽  
Structure Constant ◽  
Interaction Parameters ◽  
Cluster Approach ◽  
Hyperfine Structure Constant ◽  
Mixing Coefficients ◽  
Superhyperfine Interaction ◽  
Unpaired Spin ◽  
Orbital Mixing ◽  
Spin Densities

The hyperfine structure constant A and the superhyperfine interaction parameters Aʹ and Bʹ of Cs2GeF6:Mn4+ are theoretically studied by the cluster approach. The orbital mixing coefficients and the unpaired spin densities in 2s, 2pσ and 2pπ fluorine orbitals are obtained from the optical spectra and the impurity-ligand distance of the studied system. Based on a uniform scheme, the parameters A, Aʹ and Bʹ (as well as the g factor) are reasonably explained. The results are discussed, and the unpaired spin densities of the 2s, 2pσ and 2pπ orbitals of the ligand F− are compared with those in previous works.

Theoretical Studies of the Spin Hamiltonian Parameters for Fe0 and Mn– in Silicon Center

2013 ◽  
Vol 634-638 ◽  
pp. 2518-2522
Author(s):  
Min Quan Kuang ◽  
Shao Yi Wu ◽  
Bo Tao Song ◽  
Xian Fen Hu
Keyword(s):  
Experimental Data ◽  
Hyperfine Structure ◽  
Theoretical Studies ◽  
Spin Hamiltonian ◽  
Cluster Approach ◽  
Valence States ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
Theoretical Results ◽  
Good Agreement

The spin Hamiltonian parameters (g factors and the hyperfine structure constants) for the octahedral interstitial Fe0and Mn in silicon are theoretically investigated using the perturbation formulas of these parameters for a 3d8ion under octahedral environments based on the cluster approach. The theoretical results show good agreement with the experimental data, and the ligand contributions should be considered due to the strong covalency of the systems. The interstitial occupation of the above novel 3d8impurities of rare valence states in silicon is discussed.

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