General solution of the spin Hamiltonian for complex electron nuclear double resonance spectra

1981 ◽  
Vol 59 (2) ◽  
pp. 298-304 ◽  
Author(s):  
M. E. Ziaei
Keyword(s):  
Double Resonance ◽  
Spin Transfer ◽  
Nearest Neighbour ◽  
Spin Hamiltonian ◽  
Electron Nuclear Double Resonance ◽  
Order Of Magnitude ◽  
Transfer Parameters ◽  
Fluorine Ions ◽  
Host Lattices ◽  
The Magnetic Field

An electron nuclear double resonance investigation of CsCdF3:M (M = Mn2+, Ni2+, Cr3+, and Co2+) has been carried out to measure the transferred hyperfine interaction (thfi) between M and nearest neighbour fluorine ions. A general spin Hamiltonian which takes account of the multiplicity of the interacting nuclei, is solved for a general orientation of the magnetic field. An example is given to show that theory agrees well with experiment. Spin transfer parameters obtained are of similar order of magnitude for the same ions in similar host lattices.

Hyperfine Interaction of Nitrogen Donor in 4H-SiC Studied by Pulsed-ENDOR

2005 ◽  
Vol 483-485 ◽  
pp. 351-354 ◽  
Author(s):  
Nguyen Tien Son ◽  
Junichi Isoya ◽  
Satoshi Yamasaki ◽  
Erik Janzén
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Hyperfine Interaction ◽  
Spin Density ◽  
Basal Plane ◽  
Double Resonance ◽  
Nearest Neighbour ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Nitrogen Donor ◽  
Electron Paramagnetic

Shallow N donors in n-type 4H-SiC were studied by electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR). For the N donor at the cubic site (Nk) in 4H-SiC, the hyperfine (hf) constants of the interaction with the nearest neighbour (NN) 29Si atom along the c axis were determined as A = 41.07 MHz and A^ = 41.31 MHz. For other three NN Si atoms in the basal plane, the hf tensor has C1h symmetry and the principal values Axx = 5.94 MHz, Ayy = 5.06 MHz and Azz = 14.25 MHz. Our EPR and ENDOR observations unambiguously confirm that the N donor occupies the C site in 4H-SiC lattice and also reveal a considerable amount of the spin density of Nk (~23.9%) which was not obtained in previous studies.

Electron nuclear double resonance of the divalent europium ion

1962 ◽  
Vol 267 (1329) ◽  
pp. 283-294 ◽  
Keyword(s):  
Resonance Spectrum ◽  
Double Resonance ◽  
Spin Hamiltonian ◽  
Electron Nuclear Double Resonance ◽  
Europium Ion ◽  
Divalent Europium ◽  
Higher Order Terms ◽  
Measured Line ◽  
G Value ◽  
Line Positions

The electron nuclear double resonance spectrum of both isotopes 151 Eu and 163 Eu has been measured in a single crystal of calcium fluoride containing about 0.01 % Eu 2+ . As the lines were narrow ( ~ 10kc/s) the hyperfine structure parameter and the nuclear g-value were measured to high precision giving the following values: A 151 = -102.9069±0.0013 Mc/s, A 153 = -45.6730±0.0025 Mc/s B 151 = -0.7855±0.0052 Mc/s, B 153 = -2.0294 ±0.0068 Mc/s, gI 151 = - 7.4969±0.0020 (x 10 -4 )β, gI 153 = - 3.3125±0.0030 (x 10 -4 )β. In order to fit the measured line positions to the spin Hamiltonian which is usually assumed for the system it was necessary to add small higher-order terms. The results of these measurements are compared with the precise atomic beam measurement on Eu.

Electron spin resonance studies of 53Cr3+ and VO2+ ions in AlCl3∙6H2O

1976 ◽  
Vol 54 (2) ◽  
pp. 217-222 ◽  
Author(s):  
K. Pack ◽  
A. Manoogian
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Double Resonance ◽  
Zero Field ◽  
Spin Hamiltonian ◽  
Zero Field Splitting ◽  
Electron Nuclear Double Resonance ◽  
Spin Resonance ◽  
Impurity Doping ◽  
Static Distortion

The electron-nuclear double resonance (ENDOR) of 53Cr3+ ions and the electron spin resonance (ESR) of VO2+ ions are studied in single crystals of AlCl3∙6H2O. The ENDOR measurements are done at 4.2 K while the resonance of VO2+ is studied at room temperature. The sign of the Cr3+ spin Hamiltonian zero field splitting parameter D is found to be negative while the anisotropic hyperfine parameter has the relation A < B. It is concluded that the octahedron of waters surrounding the chromium ion is trigonally compressed. The value of the 53Cr3+ quadrupole interaction parameter Q′ is nearly the same as that found previously in the cesium alums even though the D value is considerably smaller in AlCl3∙6H2O. This indicates that Q′ is independent of D at 4.2 K in these salts and the expected proportionality [Formula: see text], which is based on a purely static distortion for the octahedron of waters surrounding the Cr3+ ion, does not hold. The resonance results for VO2+ show the nature of the two inequivalent but otherwise similar Al∙6H2O complexes in the unit cell. The VO2+∙5H2O complexes associated with the two types of aluminum sites are found to be rotated relative to each other by an angle of 33 ± 3° in the plane perpendicular to the crystal c axis. A comparison of the spin Hamiltonian parameters of VO2+ and 53Cr3+ in AlCl3∙6H2O with those obtained previously in CsAl alum indicates that the Al∙6H2O complexes in CsAl alum are more susceptible to distortion upon impurity doping than are those in AlCl3∙6H2O.

The double resonance of cobalt ions in magnesium oxide

1962 ◽  
Vol 266 (1324) ◽  
pp. 84-94 ◽  
Keyword(s):  
Single Crystals ◽  
Magnesium Oxide ◽  
Double Resonance ◽  
Spin Hamiltonian ◽  
Electron Nuclear Double Resonance ◽  
Cobalt Ions

Electron nuclear double resonance has been carried out in single crystals of MgO containing Co 2± . An accurate check of the spin-Hamiltonian has been made and the relevant parameters measured as A = 290.55 ± 0.06 Mc/s, g' N β N /gβ = 2.34 ± 0.02 x 10 -4 .

Generalized spin-Hamiltonian for paramagnetic ions in crystals. I. General formalism and its application to cubic crystalline symmetry

1964 ◽  
Vol 277 (1368) ◽  
pp. 76-91 ◽  
Keyword(s):  
Double Resonance ◽  
Rare Earth Ions ◽  
Spin Hamiltonian ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Zeeman Field ◽  
Dependent Part ◽  
Field Symmetry ◽  
Paramagnetic Ions ◽  
Crystalline Symmetry

In view of the limitations of the usual spin-Hamiltonian for characterizing exactly the low-lying levels of the paramagnetic ions in crystals, as evident from some recent electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) experiments on iron-transition group and rare-earth ions, a method is described here for deducing a general spin-Hamiltonian determined exclusively by the crystal-field symmetry. The Hamiltonian thus derived obviously includes all possible independent spin-operators, and, in general, has more terms than those considered in the usual spin-Hamiltonian. The method has been applied to the case of cubic crystalline symmetry, and the spin-Hamiltonian is written out correctly for the Zeeman field (H) independent part and the linearly field-dependent part, for all ions with both electron spin S and nuclear spin I up to 2. Terms which are quadratic in H are considered for spin values S and I up to 1 only. Relative importance of the independent operators are discussed with particular reference to two cases: Co 2+ in eight co-ordinated cubic compounds and Yb 3+ in CaF 2 , which are expected to be two extreme examples of the effect of the excited levels on the ground state. Some of the terms which are usually neglected in the usual spin-Hamiltonian are shown to make significant contributions to the spin-levels. The importance of the terms quadratic in Zeeman field is emphasized for precise ENDOR experiments.

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