Theoretical explanation of spin-Hamiltonian parameters and local structure for the orthorhombic MnO42− clusters in K2SO4:Mn6+ crystal

2017 ◽  
Vol 31 (22) ◽  
pp. 1750154
Author(s):  
Ning Wang ◽  
Linhua Xie ◽  
Chao Tu
Keyword(s):  
Local Structure ◽  
Coupling Model ◽  
Theoretical Explanation ◽  
Spin Orbit Coupling ◽  
Spin Hamiltonian ◽  
Third Order ◽  
The Third ◽  
Double Spin ◽  
Structure Constants ◽  
Hamiltonian Parameters

In this paper, based on the double-spin–orbit-coupling model, the third-order perturbation formulas of the crystal field (CF) mechanism and the charge-transfer (CT) mechanism, the spin-Hamiltonian parameters ([Formula: see text] factors: [Formula: see text], [Formula: see text], [Formula: see text] and hyperfine structure constants [Formula: see text]: [Formula: see text], [Formula: see text], [Formula: see text]) and the optical spectra of K2SO4:Mn[Formula: see text] crystal are theoretically explained. The contributions of the CF mechanism and the CT mechanism to the spin-Hamiltonian parameters are calculated and compared, and the results show that the contribution of the CT mechanism cannot be ignored when calculating the spin-Hamiltonian parameters of crystals doped with Mn[Formula: see text] ions. Meanwhile, the local structure of the impurity ions in the crystal is studied and the CF parameters of the crystal are acquired.

Investigations of the spin Hamiltonian parameters for VO2+ ions in KZnClSO4 ⋅ 3H2O single crystals

2017 ◽  
Vol 31 (02) ◽  
pp. 1650262
Author(s):  
Chao Tu ◽  
Linhua Xie ◽  
Xiangrong Du
Keyword(s):  
Single Crystals ◽  
Coupling Model ◽  
Spin Hamiltonian ◽  
Third Order ◽  
Ion Clusters ◽  
Mechanism Model ◽  
Double Spin ◽  
State Formula ◽  
High Valence State ◽  
Hamiltonian Parameters

The spin Hamiltonian parameters of VO[Formula: see text] in KZnClSO[Formula: see text]3H2O single crystals are calculated from the third-order perturbation formulas based on the double spin–orbit coupling model for the tetragonal transition-ion clusters in crystals with the ground state [Formula: see text]. In the paper, both the crystal-field (CF) mechanism and the charge-transfer (CT) mechanism (double-mechanism model) are considered to calculate the spin Hamiltonian parameters. The calculated results are in agreement with the experimental data. Moreover, the calculated results show that the CT mechanism cannot be omitted for a high-valence state V[Formula: see text] ions in KZnClSO[Formula: see text]3H2O single crystals. The tetragonal field parameters are also acquired in the paper.

Investigation of the Spin Hamiltonian Parameters of Yb3+ in CaWO4 Crystal

2004 ◽  
Vol 59 (12) ◽  
pp. 943-946 ◽  
Author(s):  
Hui-Ning Dong ◽  
Shao-Yi Wu
Keyword(s):  
Hyperfine Structure ◽  
Local Structure ◽  
Reasonable Agreement ◽  
Second Order ◽  
Order Perturbation ◽  
Superposition Model ◽  
Spin Hamiltonian ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
G Factors

In this paper, the spin Hamiltonian parameters g factors g∥ and g⊥ of Yb3+ and hyperfine structure constants A∥ and A⊥ of 171Yb3+ and 173Yb3+ in CaWO4 crystal are calculated from the two-order perturbation formulae. In these formulae, the contributions of the covalence effects, the admixture between J =7/2 and J =5/2 states as well as the second-order perturbation are included. The needed crystal parameters are obtained from the superposition model and the local structure of the studied system. The calculated results are in reasonable agreement with the observed values. The results are discussed.

INVESTIGATIONS OF THE SPIN HAMILTONIAN PARAMETERS AND THE LOCAL STRUCTURE FOR THE RHOMBICCu2+CENTER IN RUTILE

2010 ◽  
Vol 24 (22) ◽  
pp. 2357-2364 ◽  
Author(s):  
HUA-MING ZHANG ◽  
SHAO-YI WU ◽  
PEI XU ◽  
LI-LI LI
Keyword(s):  
Local Structure ◽  
Impurity Center ◽  
Angular Distortion ◽  
Spin Hamiltonian ◽  
Rhombic Distortion ◽  
Calculation Results ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Structure Constants ◽  
Hamiltonian Parameters

The spin Hamiltonian parameters (the anisotropic g factors and the hyperfine structure constants) and the local structure for the rhombic Cu2+center in rutile ( TiO2) are theoretically investigated using the formulas of these parameters for a 3d9ion in rhombically elongated octahedra. From the studies, the planar impurity-ligand bond angle is found to be about 5.8° larger than that for the host Ti4+site due to the Jahn–Teller effect via bending the planar Cu2+– O2-bonds, which yields much smaller rhombic distortion in the impurity center. The theoretical spin Hamiltonian parameters based on the above local angular distortion show good agreement with the experimental data, and the improvement of the calculation results are also achieved as compared with those of the previous works.

INVESTIGATIONS OF THE EPR PARAMETERS FORDy3+CENTER INZrSiO4CRYSTAL

2010 ◽  
Vol 24 (03) ◽  
pp. 289-296 ◽  
Author(s):  
HUI-NING DONG ◽  
DENG-FENG LI ◽  
JUN LIU ◽  
DAVID J. KEEBLE
Keyword(s):  
Crystal Field ◽  
Tetragonal Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Hamiltonian ◽  
Field Interaction ◽  
Paramagnetic Resonance ◽  
Epr Parameters ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
G Factors

The electronic paramagnetic resonance g factors g‖, g⊥of Dy3+centers and the hyperfine structure constants A‖and A⊥of161Dy3+and163Dy3+isotopes in ZrSiO4crystal are theoretically studied from the perturbation formulas of the spin Hamiltonian parameters for a 4f9ion in tetragonal symmetry. In these formulas, the contributions to g factors due to the J-mixing among the ground6H15/2, the first excited6H13/2and second excited6H11/2states via crystal-field interaction, the admixtures among the states with the same J value via spin-orbit coupling interaction and the interactions between the lowest Kramers doublet Γγ and other 20 Kramers doublets ΓXwithin the states6HJ(J=15/2, 13/2 and 11/2) via crystal-field and orbital angular momentum interactions are considered. The calculated EPR parameters show reasonable agreement with the observed values. The results are 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.

STUDIES ON THE LOCAL STRUCTURE AND THE SPIN HAMILTONIAN PARAMETERS FOR THE TRIGONAL Mn2+ CENTER IN Bi4Ge3O12

2008 ◽  
Vol 22 (14) ◽  
pp. 1381-1387 ◽  
Author(s):  
XUE-FENG WANG ◽  
SHAO-YI WU ◽  
ZHI-HONG ZHANG ◽  
LI-HUA WEI ◽  
YUE-XIA HUA
Keyword(s):  
Hyperfine Structure ◽  
Local Structure ◽  
Zero Field ◽  
Spin Hamiltonian ◽  
Zero Field Splitting ◽  
Trigonal Symmetry ◽  
Oxygen Octahedron ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
Good Agreement

The local structure and the spin Hamiltonian parameters (the zero-field splitting D, the g factors g//, g⊥ and the hyperfine structure constants A// and A⊥) for the trigonal Mn 2+ center in Bi 4 Ge 3 O 12 are theoretically studied from the perturbation formulas of these parameters for a 3d5 ion in trigonal symmetry. The impurity Mn 2+ replacing host Bi 3+ is not found to occupy the exact Bi 3+ site but to suffer a large off-center displacement by about 0.36 Å towards the center of the oxygen octahedron along the C3-axis due to the size and charge mismatching substitution. The calculated spin Hamiltonian parameters based on the above displacement show good agreement with the observed values. The results and the mechanism of the impurity displacement are discussed.

Studies of the Axial Shift and the Spin Hamiltonian Parameters for Mn2+ in a CdS Crystal

2009 ◽  
Vol 294 ◽  
pp. 77-83
Author(s):  
Xue Feng Wang ◽  
Shao Yi Wu ◽  
Yue Xia Hu ◽  
Pei Xu
Keyword(s):  
Reasonable Agreement ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Hamiltonian ◽  
Cluster Approach ◽  
Zero Field Splitting ◽  
Ligand Orbital ◽  
Axial Shift ◽  
Structure Constants ◽  
Hamiltonian Parameters

The axial shift and the spin Hamiltonian parameters (zero-field splitting D, the g factors and the hyperfine structure constants A// and A) for Mn2+ in a CdS crystal are studied theoretically in this work. The calculations are carried out by using the perturbation formulae of these parameters for a 3d5 ion under trigonally distorted tetrahedra based upon the cluster approach, where the ligand orbital and spin-orbit coupling contributions are taken into account in a uniform way. From the studies, the impurity Mn2+ is found not to occupy the host Cd2+ site exactly but to experience a small outward shift of 0.018 Å away from the ligand triangle along the C3 axis. The above impurity axial shift leads to a much smaller trigonal distortion than the host Cd2+ site in CdS. The calculated spin Hamiltonian parameters are in reasonable agreement with the experimental data.

Investigations of the spin Hamiltonian parameters for the cubic Mn2+ centers in ZnX (X = S, Se, Te) and CdTe

2010 ◽  
Vol 88 (5) ◽  
pp. 301-306 ◽  
Author(s):  
Xue-Feng Wang ◽  
Shao-Yi Wu ◽  
Li-Li Li ◽  
Shan-Xiang Zhang
Keyword(s):  
Charge Transfer ◽  
Hyperfine Structure ◽  
Crystal Field ◽  
Pure Spin ◽  
Spin Orbit Coupling ◽  
Spin Hamiltonian ◽  
Structure Constants ◽  
Hamiltonian Parameters ◽  
Good Agreement ◽  
G Factors

The spin Hamiltonian parameters (g factors and the hyperfine structure constants) for the cubic Mn2+ centers in ZnX (X = S, Se, Te) and CdTe are investigated theoretically using the perturbation formulas of these parameters for a tetrahedral 3d5 cluster containing both the crystal-field and charge-transfer contributions. The relevant molecular orbital coefficients are uniformly determined from the cluster approach, and the calculated spin Hamiltonian parameters are in good agreement with the observed values. The g-shifts of the g factors related to the pure spin value gs (≈ 2.0023) arising from the charge transfer contributions are opposite (positive) in sign and much larger in magnitude than those from the crystal field contributions. On the other hand, the contributions from the charge-transfer mechanism to the hyperfine structure constants are the same in sign and about 20%–30% in magnitude of those from the crystal-field mechanism. The importance of the charge transfer contributions increases significantly with the increase of the covalency and the spin–orbit coupling coefficient of the ligand, i.e., S2− < Se2− < Te2−.

Investigations on the spin Hamiltonian parameters of Cu(2) site in (Tl0.5Pb0.5)Sr2CaCu2O7 superconductors

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542018
Author(s):  
Xian-Fen Hu ◽  
Shao-Yi Wu ◽  
Zhi-Hong Zhang ◽  
Min-Quan Kuang
Keyword(s):  
Hyperfine Structure ◽  
Ground State ◽  
Reduction Factor ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Spin Hamiltonian ◽  
Core Polarization ◽  
Ligand Orbital ◽  
Structure Constants ◽  
Hamiltonian Parameters

The spin Hamiltonian parameters ([Formula: see text] factors and hyperfine structure constants) of the five-fold coordinated Cu(2) site in [Formula: see text] superconductors are investigated from the high order perturbation formulas of these parameters for a [Formula: see text] ion in tetragonally elongated octahedron. The observed anisotropies [Formula: see text] and [Formula: see text] are ascribed to the [Formula: see text] ground state for [Formula: see text] under octahedral tetragonal elongation distortion. The comparable magnitudes of the parallel and perpendicular hyperfine structure constants may be illustrated by the small core polarization constant and the reduction factor [Formula: see text]. The ligand orbital and spin–orbit coupling contributions are found to be important due to significant covalency and should be considered in the calculations.

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.

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