An investigation on the EPR parameters and tetragonal distortion for Cu$$^{\mathrm {2+}}$$ center in Mg(CH$$_{\mathrm {3}}$$COO)$$_{\mathrm {2}}\cdot $$ 4H$$_{\mathrm {2}}$$O Crystal

2021 ◽  
Vol 75 (4) ◽  
Author(s):  
B. F. Liu ◽  
M. L. Qin ◽  
Y. P. Li ◽  
E. J. Liao ◽  
M. Y. Liu ◽  
...  
Keyword(s):  
Tetragonal Distortion ◽  
Epr Parameters

Studies of the EPR Parameters and the Local Tetragonal Distortion of V4+-Doped SrTiO3 Crystal

2005 ◽  
Vol 60 (6) ◽  
pp. 433-436 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Ying-Juan Fan ◽  
Xiao-Xuan Wu
Keyword(s):  
Coupling Parameter ◽  
Tetragonal Distortion ◽  
Spin Orbit ◽  
Pure Crystal ◽  
Oxygen Octahedron ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Epr Parameters ◽  
Structure Constants ◽  
Impurity Ion

The EPR parameters (g factors g||, g⊥ and hyperfine structure constants A||, A⊥) of V4+ ion in the tetragonal phase of SrTiO3 crystal were studied by high-order perturbation formulas based on a two-spin-orbit-parameter model, where the contributions from the spin-orbit-coupling-parameter of central 3dn ion and that of ligands are considered. It is found that the oxygen octahedron surroundingthe impurity ion V4+ changes from elongation along the tetragonal axis in the pure crystal to compression and the magnitude of tetragonal distortion of oxygen octahedron (characterized by |ΔR|=|R||−R⊥|) inV4+ center is much greater than the corresponding value in the pure crystal. The cause related to the strong Jahn-Teller effect is discussed.

scholarly journals Theoretical Studies of the EPR Parameters and the Local Structure of the Tetragonal Fe+ Center in KTaO3

2005 ◽  
Vol 60 (1-2) ◽  
pp. 101-105
Author(s):  
Shao-Yi Wu ◽  
Hui-Ning Dong ◽  
Xiu-Ying Gao
Keyword(s):  
Local Structure ◽  
Impurity Center ◽  
Tetragonal Distortion ◽  
Zero Field ◽  
Theoretical Studies ◽  
Zero Field Splitting ◽  
Quadrupole Shift ◽  
Epr Parameters ◽  
Nuclear Quadrupole ◽  
G Factors

The EPR parameters (zero-field splitting D and g factors g‖ and g⊥) and the local structure for the tetragonal Fe+ center in KTaO3 are theoretically studied by using the perturbation formulas of the EPR parameters for a 3d7 ion in tetragonally distorted dodecahedra. Based on these studies, we find that the impurity Fe+ may not locate on the regular dodecahedral K+ site but suffer a large off-center displacement ΔZ (≈ 0.43 Å) along one of the 100 〈or C4〉 axes, which is responsible for the large tetragonal distortion of the impurity center. The displacement ΔZ obtained in this work is comparable with that (≈ 0.46 Å ) of a similar monovalent Li+ on K+ site of KTaO3 obtained from the nuclear quadrupole shift and can be regarded as reasonable. The calculated g factors, particularly the anisotropy Δg (= Kg⊥ −g‖) based on the above displacement, agree with the observed values.

Studies of the EPR parameters and tetragonal distortion for the Cu2+ center in aluminium oxide

2020 ◽  
Vol 175 (9-10) ◽  
pp. 952-960
Author(s):  
Y. D. Li ◽  
B. J. Chen ◽  
C. Yan ◽  
H. M. Zhang ◽  
W. B. Xiao
Keyword(s):  
Aluminium Oxide ◽  
Tetragonal Distortion ◽  
Epr Parameters

Local Lattice Distortion near Co2+ in SrLaAlO4 Crystal

2001 ◽  
Vol 56 (8) ◽  
pp. 557-560 ◽  
Author(s):  
Shao-Yi Wu ◽  
Wen-Chen Zheng
Keyword(s):  
Ionic Radius ◽  
Lattice Distortion ◽  
Tetragonal Distortion ◽  
Host Crystal ◽  
Local Lattice Distortion ◽  
Oxygen Octahedron ◽  
Local Distortion ◽  
Local Lattice ◽  
Epr Parameters ◽  
Metal Ligand

Abstract The local tetragonal distortion in the vicinity of substitutional Co2+ impurities in SrLaAlO4 crystal is studied by fitting the calculated EPR parameters g\\, g⟂, A\\ and A⟂ to the observed values. The result shows that the local distortion is mainly due to the elongation of metal-ligand distance R± perpendicular to the C4 axis. This point is consistent with the expectation based on the consideration of ionic radius sum. This smaller tetragonal distortion of the oxygen octahedron surrounding the Co2+ impurity than that in the host crystal is supported by the result obtained in Cr3+-doped SrLaAlO4 crystal. -P a cs: 61.70Rj; 76.30Fc; 71.70Ch

O-O bond activation with cobalt(II)-ethylenediamine complexes in ion-exchange resins

1980 ◽  
Vol 45 (6) ◽  
pp. 1780-1784 ◽  
Author(s):  
Atanas Andreev ◽  
Lachezar Prahov ◽  
Dimitar Shopov
Keyword(s):  
Ion Exchange ◽  
Bond Activation ◽  
Catalytic Properties ◽  
Decomposition Reaction ◽  
Ion Exchange Resins ◽  
Hydrogen Peroxide Decomposition ◽  
Surface Complexes ◽  
Peroxide Decomposition ◽  
Epr Parameters ◽  
Exchange Resins

The formation of Oxygen paramagnetic adducts of Co(II) containing ion-exchange resins in the presence of adsorbed ethylenediamine has been found. The EPR parameters of a complex of the type Co(III) (en)2O-2 and of O-2 species formed in the presence of Co(en)2+3 have been described. The catalytic properties of Co-ethylenediamine surface complexes with respect to the hydrogen peroxide decomposition reaction have been investigated and a probable mechanism has been suggested.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

scholarly journals Modeling of EPR Parameters for Cu(II): Application to the Selective Reduction of NOx Catalyzed by Cu-Zeolites

2018 ◽  
Vol 61 (9-11) ◽  
pp. 810-832 ◽  
Author(s):  
Estefanía Fernández ◽  
Marta Moreno-González ◽  
Manuel Moliner ◽  
Teresa Blasco ◽  
Mercedes Boronat ◽  
...  
Keyword(s):  
Selective Reduction ◽  
Selective Reduction Of Nox ◽  
Epr Parameters ◽  
Reduction Of Nox

DFT Calculations of EPR Parameters in an Ionic Lattice of [M(CN)4]3-(M = Ni, Pd, Fe, Ru, Os) Complexes

2007 ◽  
Vol 111 (30) ◽  
pp. 7218-7222 ◽  
Author(s):  
Marcos C. Esteves ◽  
Ney V. Vugman ◽  
Alexandre A. Leitão ◽  
Carlos E. Bielschowsky
Keyword(s):  
Dft Calculations ◽  
Epr Parameters ◽  
Ionic Lattice

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.

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