Journal ArticleDOI
EPR and 19F-ENDOR of Cr3+ Impurity Centres in K2ZnF4 and K2MgF4
TLDR
In this article, the EPR spectra of three kinds of Cr 3+ centres in K 2 ZnF 4 and K 2 MgF 4 were reported, and the values of the parameters ( g // - g ⊥ ) and D in the spin Hamiltonian were discussed by considering the effective negative charge distribution surrounding the Cr 3 + ion.Abstract:
The EPR spectra of three kinds of Cr 3+ centres in K 2 ZnF 4 and K 2 MgF 4 are reported. The Cr 3+ ion in each centre replaces the divalent cation substitutionally. The centre I (tetragonal symmetry) is ascribed to a vacancy-free Cr 3+ ion. In centre II (nearly-trigonal) a vacancy is present at the nearest K + site and in centre III (nearly-tetragonal) at divalent cation site. For each centre the values of the parameters ( g // - g ⊥ ) and D in the spin Hamiltonian are discussed by considering the effective negative charge distribution surrounding the Cr 3+ ion. In the vacancy-associated centres the values of D are interpreted by superposition of two uniaxial spin-Hamiltonian terms. Results of 19 F-ENDOR of K 2 MgF 4 : Cr 3+ are also presented.read more
Citations
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Journal ArticleDOI
Impurity-ligand distances derived from magnetic resonance and optical parameters
TL;DR: In this paper, a non-empirical method for obtaining information from EPR, ENDOR and optical data on the true impurity-ligand distance, R, as well as the true variations, ΔR, induced by chemical and hydrostatic pressures, phase transitions in the host material and temperature changes are discussed through this work.
Journal ArticleDOI
Electron nuclear double resonance of intrinsic and impurity centers in ionic crystals
TL;DR: In this paper, a review of the application of the endor-induced ESR and double-ENDOR methods for the determination of defect structures from hyperfine and superhyperfine interactions and the basic ideas of the analysis of endor spectra are briefly described.
Journal ArticleDOI
Luminescence of the new elpasolite Rb2KGaF6 doped with Cr3
TL;DR: In this article, a comparison of the experimental vibrational frequencies and zero-phonon line with those for K 2 NaAlF 6 :Cr 3+ indicates that the Cr 3+ -F − distance is about 1.5 pm larger for Rb 2 KGaF6 :Cr3+, which can be mainly explained through the vibrational modes of the CrF 6 3− complex.
Journal ArticleDOI
EPR Study of Cr3+ Centres in Rb2ZnF4, Rb2CdF4 and Cs2CdF4 Crystals
TL;DR: In this paper, the fine structure parameters D and E are interpreted by two uniaxial spin-Hamiltonian terms along the c-axis of the host crystal and along the direction of the Cr 3+ -V M or Cr 3 + -Li + pair.
Journal ArticleDOI
Colour due to Cr3+ ions in oxides: a study of the model system MgO:Cr3+.
TL;DR: The calculated electrostatic potential, VR(r), related to ER(r,), is found to be attractive when the electronic density is lying along <110> directions and |r| > 1 Å driven by the first shell of twelve Mg(2+) ions.
References
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Journal ArticleDOI
Electron spin resonance of axially symmetric Cr3+ centres in KMgF3 and KZnF3
TL;DR: In this article, the ESR spectra of five Cr3+ centers in KMgF3 and KZnF3 are reported. All are axially symmetric and can be described by the spin-Hamiltonian H=g/sub /// beta BzSz+gperpendicular to beta (BxSx+BySy)+D(Sz2-1/3S(S+1)) with S=3/2.
Journal ArticleDOI
Hyperfine Spectrum of Chromium 53 in Al 2 O 3
TL;DR: In this paper, a positive value of 48.5 Mc/sec was obtained for the hyperfine coupling constant and -0.04 MC/sec for the quadrupole coupling constant.
Journal ArticleDOI
Anisotropic Hyperfine Interaction of Cr53 in Chromium (III) Acetylacetonate
TL;DR: In this paper, the ESR spectra of chromium (III) acetylacetonate in single crystals of cobalt (III), aluminum (Aluminum Acetonate) and cobalt(III) acetonate were studied.
Journal ArticleDOI
Electron-nuclear double resonance of Mn2+ in quadratic-layer fluorides. Nuclear quadrupole interaction and zero-point spin deviation
TL;DR: In this paper, the spin-hamiltonian parameters for Mn2+ in K2MgF4, K2ZnF4 and Rb2CdF4 have been determined by means of ENDOR experiments at 4.2K.
Journal ArticleDOI
The hyperfine interactions of fluorine ions in the vicinity of Cr3+ and Cr+ in KMgF3. I. 19F and 53Cr ENDOR measurements
J J Davies,K Horai +1 more
TL;DR: In this article, Endor measurements on the nuclei of the first, second and third nearest sets of fluorine ions to Cr3+ and Cr+ in KMgF3 are reported, and the main results concern the second nearest, whose hyperfine tensors are found in both cases to show significant departures from the values expected on a purely dipolar basis.