Efficient calculation of electron paramagnetic resonance g-tensors by multireference configuration interaction sum-over-state expansions, using the atomic mean-field spin–orbit method

2003 ◽  
Vol 118 (21) ◽  
pp. 9552-9562 ◽  
Author(s):  
Scott Brownridge ◽  
Friedrich Grein ◽  
Jörg Tatchen ◽  
Martin Kleinschmidt ◽  
Christel M. Marian
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Configuration Interaction ◽  
Mean Field ◽  
Orbit Method ◽  
Spin Orbit ◽  
Paramagnetic Resonance ◽  
Efficient Calculation ◽  
Electron Paramagnetic

INVESTIGATIONS OF ELECTRON-PARAMAGNETIC-RESONANCE PARAMETERS OF OCTAHEDRAL (CrO6)9- and (MnO6)8- CLUSTER IN MgTiO3:Cr3+, SrTiO3:Cr3+ AND SrTiO3:Mn4+ CRYSTALS

2011 ◽  
Vol 25 (21) ◽  
pp. 1779-1785
Author(s):  
MINJIE WANG ◽  
LIANXUAN ZHU ◽  
JIANLIANG DANG
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Crystal Field ◽  
Valence State ◽  
Spin Orbit ◽  
Contribution Rate ◽  
Paramagnetic Resonance ◽  
Epr Parameters ◽  
Experimental Values ◽  
Electron Paramagnetic ◽  
G Factors

The complete high-order perturbation formulas are established by both crystal-field (CF) and charge-transfer (CT) mechanisms. The EPR g factors of MgTiO 3: Cr 3+, SrTiO 3: Cr 3+ and SrTiO 3: Mn 4+ crystals are calculated from the formulas. The calculations of the EPR g factors are in agreement with the experimental values. The contribution rate of the CT mechanism (|ΔgT/ΔgF|) to EPR parameters, increases with the growth of the valence state for the 3dn ions in the crystals. For the higher valence state 3d3 ion Mn 4+ in crystals, the explanation of the EPR parameters reasonably involves both CF and CT mechanisms. The g values are also given from one-spin-orbit-parameter model and crystal-field (CF) mechanism for comparison.

On The EPR Parameters of Divalent Cobalt in ZnX (X = S, Se, Te) And CdTe

2004 ◽  
Vol 59 (12) ◽  
pp. 938-942 ◽  
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Charge Transfer ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Paramagnetic Resonance ◽  
A Value ◽  
Epr Parameters ◽  
Divalent Cobalt ◽  
Structure Constants ◽  
Electron Paramagnetic

The electron paramagnetic resonance (EPR) parameters g and the hyperfine structure constants A of Co2+ in ZnX (X = S, Se, Te) and CdTe are studied, using the perturbation formulas of the EPR parameters for a 3d7 ion in tetrahedra based on two mechanism models. In these formulas, both the contributions from the conventional crystal-field (CF) mechanism and those from the charge-transfer (CT) mechanism are taken into account. According to the investigations, the sign of the g-shift ΔgCT from the CT mechanism is the same as ΔgCF from the CF mechanism, whereas the contributions to the A value from the CF and CT mechanisms have opposite signs. Particularly, the contributions to the EPR parameters from the CT mechanism increase rapidly with increase of the spin-orbit coupling coefficient of the ligand and the covalency effect of the systems, i. e. S2− < Se2− < Te2−.

Theoretical investigations of electron paramagnetic resonancegfactors in ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals

2012 ◽  
Vol 45 (5) ◽  
pp. 972-975
Author(s):  
Lianxuan Zhu ◽  
Minjie Wang
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Charge Transfer ◽  
Coupling Effect ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Paramagnetic Resonance ◽  
Theoretical Investigations ◽  
The One ◽  
Electron Paramagnetic

The electron paramagnetic resonance (EPR)g-factor formulas are constructed for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals based on the contributions of the charge-transfer levels and the spin-orbit coupling effect of the central ion and the ligands. The EPRgfactors are calculated from these formulas, and the calculated values agree well with the experimental ones. The contribution rates of the charge-transfer levels are 10.1, 7.6 and 24.9% for ZnSe:Ti2+, CdTe:Ti2+and ZnSe:V3+crystals, respectively. Thegfactors obtained from the one-spin-orbit-parameter model are also given for comparison.

Investigations of the EPR Parameters and Local Structures for Two Tetragonal Cr3+ Centers in NH4Cl Crystal

2001 ◽  
Vol 56 (3-4) ◽  
pp. 326-328 ◽  
Author(s):  
Shao-Yi Wu ◽  
Wen-Chen Zheng
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Room Temperature ◽  
Zero Field ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Resonance Parameters ◽  
Local Structures ◽  
Epr Parameters ◽  
Electron Paramagnetic

Abstract In this paper, the zero-field splittings D and g factors g||, g⟂ at room temperature for two tetragonal Cr3+ centers in NH4Cl:Cr3+ crystal have been investigated by a two-spin-orbit (S.O)-parameter model, in which both the contribution due to the S.O. coupling of central d3 ion and that of ligands are considered. From the investigations, the signs of zero-field splitting and the local structures of both centers are ob­ tained. The electron paramagnetic resonance parameters D, g|| and g⟂ of both centers are also explained.

scholarly journals Defect Structures for Fe3+, Mn2+, and Ni3+ Impurities in Wuritzite GaN Crystals

2001 ◽  
Vol 56 (6-7) ◽  
pp. 473-477 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Shao-Yi Wu ◽  
Jian Zi
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Strong Field ◽  
Zero Field ◽  
Spin Orbit ◽  
Defect Structures ◽  
Superposition Model ◽  
Paramagnetic Resonance ◽  
Impurity Ions ◽  
Epr Parameters ◽  
Electron Paramagnetic

Abstract Electron paramagnetic resonance (EPR) zero-field splittings D for Mn2+ and Fe3+ in wurtzite GaN crystals are studied from high-order perturbation formulas based on the spin-orbit mechanism in both weak- and strong-field schemes. From these studies it can be seen that the Mn2+ or Fe3+ impurity does not occupy the exact Ga3+ position, but is displaced by ΔR on the C3 axis. The displacements are confirmed from a study of the superposition model, based on which a normal value of b̅2 (Ro) ( ≈ -0 .34 (15) cm-1 ) for the Fe3+-N3- combination is suggested. The EPR parameters D, g|| and g ⟂ for Ni3+ in GaN crystals are also studied. It is found that Ni3+ is almost not displaced. The impurity displacements in GaN are discussed by considering the valences and radii of these impurity ions and the replaced Ga3+ ion. - Pacs: 61.16Hn; 76.30Fc; 71.70Ch

Interpretation of the Electron Paramagnetic Resonance Spectra of Copper(II)–Tyrosine Complex

2017 ◽  
Vol 73 (1) ◽  
pp. 75-78
Author(s):  
Xiao-Hui Xu ◽  
Min-Quan Kuang
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Mean Value ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Distortion ◽  
The Mean ◽  
Electron Paramagnetic ◽  
Ligand Bond

AbstractThe electron paramagnetic resonance (EPR) spectra of [Cu(l-tyrosine)2]n (CuA) were interpreted based on the fourth-order perturbation treatments where the contributions due to the local distortion, ligand orbit and spin-orbit coupling were included. The calculated band transitions ${{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}}$ to dxy (≈16412 cm−1) and ${{\text{d}}_{{{\text{z}}^2}}}$ (≈14845 cm−1) agree well with the band analysis results ${\text{(}}{{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}} \to {{\text{d}}_{{\text{xy}}}}$≈16410 and ${{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}} \to {{\text{d}}_{{{\text{z}}^2}}}$≈14850 cm−1). The unresolved separations ${{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}} \to {{\text{d}}_{{\text{xz}}}}$ and ${{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}} \to {{\text{d}}_{{\text{yz}}}}$ in the absorption spectra were evaluated as 26283 and 26262 cm−1, respectively. For CuA, copper chromophores in 1,3-diaminorpropane isophtalate copper(II) complex (CuB) and N-methyl-1,2-diaminoetaane-bis copper(II) polymer (CuC), the transition ${{\text{d}}_{{{\text{x}}^2} - {{\text{y}}^2}}} \to {{\text{d}}_{{\text{xy}}}}$ (=E1≈10Dq) suffered an increase with a decrease in R̅L which was evaluated as the mean value of the copper-ligand bond lengths. The correlations between the tetragonal elongation ratio ρ (=(Rz–R̅L)/R̅L) (or the ratio G=(gz–ge)/((gx+gy)/2–ge)) and the g isotropy gav (=(gx+gy+gz)/3) (or the covalency factor N) for CuA, CuB and CuC were acquired and all the results were discussed.

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