Electron paramagnetic resonance g-tensors from state interaction spin-orbit coupling density matrix renormalization group

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−.

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

Journal of Applied Crystallography ◽

10.1107/s0021889812034528 ◽

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.

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

Zeitschrift für Naturforschung A ◽

10.1515/zna-2017-0239 ◽

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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