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 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 of EPR Parameters and Local Structure for Cr3+ in NaInS2 Crystal

2005 ◽  
Vol 60 (1-2) ◽  
pp. 91-94
Author(s):  
Yang Mei ◽  
Wen-Chen Zheng ◽  
Xiao-Xuan Wu ◽  
Qing Zhoua
Keyword(s):  
Local Structure ◽  
Coupling Parameter ◽  
Orbit Coupling ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Epr Parameters ◽  
Local Angle

The EPR parameters (zero-field splitting D and g factors g‖, g⊥) of Cr3+ in a NaInS2 crystal are calculated from high-order perturbation formulas based on the two spin-orbit coupling parameter model for the EPR parameters of 3d3 ions in trigonal octahedral sites. In the calculations, both the contribution to EPR parameters from the spin-orbit coupling parameter of the central 3d3 ion and that of ligands are considered. From the calculations it is found that, to explain reasonably the EPR parameters, the local structure (in particular the local trigonal distortion angle θ ) in the vicinity of the Cr3+ impurity is different from the corresponding structure in the host crystal. The change of the local angle θ with temperature is also obtained from the temperature dependence of zero-field splitting. The results are discussed.

EPR Parameters and Local Atom-position Parameters for Co2+ Ions in CdS and CdSe Semiconductors

2004 ◽  
Vol 59 (11) ◽  
pp. 783-786 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Xiao-Xuan Wu ◽  
Yang Mei ◽  
Jian Zi
Keyword(s):  
Coupling Parameter ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Zero Field Splitting ◽  
Trigonal Symmetry ◽  
Epr Parameters ◽  
Impurity Centers ◽  
Atom Position

The EPR parameters (zero-field splitting D and g factors gII, g⊥) of Co2+ ions in CdS and CdSe semiconductors are calculated from the high-order perturbation formulas based on the cluster approach for a 3d7 ion in trigonal symmetry. These formulas include the contribution to the EPR parameters from both the spin-orbit coupling parameter of the 3d7 ion and that of the ligand. From the calculations, the local atom-position parameters u (which are different from the corresponding values in the host crystals) for the Co2+ impurity centers in both semiconductors are estimated. The results are discussed

Investigations of the EPR Parameters and Local Lattice Structure for the Rhombic Cu2+ Centre in TZSH Crystal

2016 ◽  
Vol 71 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Chao-Ying Li ◽  
Shi-Fei Liu ◽  
Jin-Xian Fu
Keyword(s):  
Lattice Structure ◽  
Spin Orbit Coupling ◽  
Paramagnetic Resonance ◽  
Local Lattice ◽  
Ligand Orbital ◽  
Epr Parameters ◽  
Structure Constants ◽  
Electron Paramagnetic ◽  
D Orbitals ◽  
Good Agreement

AbstractThe electron paramagnetic resonance (EPR) parameters [i.e. g factors gi (i=x, y, z) and hyperfine structure constants Ai] and the local lattice structure for the Cu2+ centre in Tl2Zn(SO4)2·6H2O (TZSH) crystal were theoretically investigated by utilising the perturbation formulae of these parameters for a 3d9 ion under rhombically elongated octahedra. In the calculations, the admixture of d orbitals in the ground state and the ligand orbital and spin-orbit coupling interactions are taken into account based on the cluster approach. The theoretical EPR parameters show good agreement with the observed values, and the Cu2+–H2O bond lengths are obtained as follows: Rx≈1.98 Å, Ry≈2.09 Å, Rz≈2.32 Å. The results are discussed.

Spin–orbit splitting in 2Δ states of diatomic molecules

1969 ◽  
Vol 47 (23) ◽  
pp. 2727-2730 ◽  
Author(s):  
H. Lefebvre-Brion ◽  
N. Bessis
Keyword(s):  
Diatomic Molecules ◽  
Orbit Interaction ◽  
Second Order ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Orbit Splitting ◽  
Spin Orbit Splitting ◽  
Good Agreement

The origin of the splitting of the 2Δ states arising from the σπ2 configuration is studied. For light diatomic molecules, the splitting is shown to arise from the spin–other–orbit interaction which gives a small negative value for the spin–orbit coupling constant A. Non-empirical calculations of A for the 2Δ states of the CH, NH+, and NO molecules are in good agreement with experiment. In heavier molecules, the spin–other–orbit interaction becomes negligible and the second-order spin–orbit effect is dominant.

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.

Ground state properties of actinide dioxides: A self-consistent Hubbard U approach with spin orbit coupling

2017 ◽  
Vol 06 (01) ◽  
pp. 1750006 ◽  
Author(s):  
A. Bouasria ◽  
A. Zaoui ◽  
S. Ait Abderrahmane ◽  
S. Kacimi ◽  
A. Boukortt ◽  
...  
Keyword(s):  
Magnetic Phase ◽  
Relativistic Effects ◽  
Coulomb Repulsion ◽  
Band Gaps ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Electronic Density ◽  
Spin Orbit Interactions ◽  
Good Agreement

Using Perdew–Burke–Ernzerhof [Formula: see text] formalism, we present a systematic study of the magnetic phase stability, mechanical properties, electronic density of states and band gaps of actinide dioxides ([Formula: see text]). Relativistic effects are also considered via the spin orbit coupling. The [Formula: see text] electrons behavior has been investigated as a function of the Coulomb repulsion [Formula: see text]. Lattice parameters, elastic constants and band gaps of [Formula: see text] are consistently in good agreement with the available experimental data. From [Formula: see text] calculations, all [Formula: see text] are found to be semiconductors or insulators. Our results show that the strong correlation treatment by the Coulomb potential and the spin orbit interactions are necessary to predict the accurate electronic structure of this series of materials.

scholarly journals High-precision calculation of relativistic corrections for hydrogen-like atoms with screened Coulomb potentials

2021 ◽  
Author(s):  
Hui Xie ◽  
Li Guang Jiao ◽  
Ai Liu ◽  
Y.K. Ho
Keyword(s):  
Perturbation Theory ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
First Order ◽  
Relativistic Corrections ◽  
Relativistic Mass ◽  
Mass Correction ◽  
Direct Perturbation ◽  
Good Agreement

The first-order relativistic corrections to the non-relativistic energies of hydrogen-like atom embedded in plasma screening environments are calculated in the framework of direct perturbation theory by using the generalized pseudospectral method. The standard Debye-Hückel potential, exponential cosine screened Coulomb potential, and Hulthén potential are employed to model different screening conditions and their effects on the eigenenergies of hydrogen-like atoms are investigated. The relativistic corrections which include the relativistic mass correction, Darwin term, and the spin-orbit coupling term for both the ground and excited states are reported as functions of screening parameters. Comparison with previous theoretical predictions shows that both the relativistic mass correction and spin-orbit coupling obtained in this work are in good agreement with previous estimations, while significant discrepancy and even opposite trend is found for the Darwin term. The overall relativistic-corrected system energies predicted in this work, however, are in good agreement with the fully relativistic calculations available in the literature. We finally present the scaling law of the first-order relativistic corrections and discuss the validity of the direct perturbation theory with respect to both the nuclear charge and the screening parameter.

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