The spin-phonon interaction of Ni 2+ ion pairs in KMgF 3

1970 ◽  
Vol 315 (1523) ◽  
pp. 535-549 ◽  
Keyword(s):  
Resonance Spectrum ◽  
Ion Pairs ◽  
Nearest Neighbour ◽  
Phonon Interaction ◽  
Paramagnetic Resonance ◽  
Exchange Parameters

Unexpected lines in the acoustic paramagnetic resonance spectrum of KMgF 3 :Ni 2+ are assigned to second nearest neighbour and more distant Ni 2+ ion pairs. Exchange parameters are deduced for the pairs, and the mechanism for their spin-phonon interaction is inferred to be the single-ion, ( S 1 . d . S 1 ) + ( S 2 - d . S 2 ) process.

Exchange interactions in antiferromagnetic salts of iridium. I. Paramagnetic resonance experiments

1959 ◽  
Vol 250 (1260) ◽  
pp. 84-96 ◽  
Keyword(s):  
Magnetic Susceptibility ◽  
Theoretical Analysis ◽  
Resonance Spectrum ◽  
Exchange Interactions ◽  
Ammonium Salts ◽  
Nearest Neighbour ◽  
Helium Temperature ◽  
Paramagnetic Resonance ◽  
Anisotropic Part ◽  
Rhombic Symmetry

Paramagnetic resonance methods have been used to investigate Ir-Ir exchange interactions in K 2 IrCl 6 and (NH 4 ) 2 IrCl 6 . Measurements are described of the resonance spectrum from nearest-neighbour pairs of Ir ions in semi-dilute mixed crystals where Pt is substituted for Ir. The results show that the isotropic p art of the Ir-Ir exchange, J / k , is antiferromagnetic and of magnitude 11.5 ± 1°K and 7.5 ± 1°K for the potassium and ammonium salts, respectively. There is also found to be an anisotropic part with rhombic symmetry and with magnitude of order 1 cm -1 . No lines attributable to next-nearest-neighbour pairs were found, and it is suggested that this interaction is small. The results are com pared briefly with the magnetic susceptibility experiments of Cooke et al . (part II) who find that the concentrated salts go antiferromagnetic in the liquid-helium temperature range, and also with the theoretical analysis of the superexchange mechanism given by Judd (part III).

scholarly journals Highly resolved electron paramagnetic resonance spectrum of copper(II) ion pairs in CuCe oxide

1992 ◽  
Vol 88 (4) ◽  
pp. 615-620 ◽  
Author(s):  
Antoine Aboukaïs ◽  
Abdelrhani Bennani ◽  
Cossi Faustin Aïssi ◽  
Geneviève Wrobel ◽  
Michel Guelton ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Spectrum ◽  
Resonance Spectrum ◽  
Ion Pairs ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The Electron Paramagnetic Resonance Spectrum of the Phenalane Anion

1972 ◽  
Vol 50 (10) ◽  
pp. 1523-1528 ◽  
Author(s):  
D. H. Paskovich ◽  
A. H. Reddoch
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Spectrum ◽  
Alkali Metals ◽  
Room Temperature ◽  
Resonance Spectrum ◽  
Ion Pairs ◽  
Coupling Constants ◽  
Paramagnetic Resonance ◽  
Conformational Interconversion ◽  
Electron Paramagnetic

The phenalane anion has been prepared by the reaction of alkali metals in ether solutions of both phenalane and phenalene. The electron paramagnetic resonance spectra of both the radical and of its ion pairs with sodium and with lithium in THF are reported. At room temperature there is an alternating linewidth involving the β protons caused by conformational interconversion of the axial and equatorial positions. At −80 °C the γ protons are not equivalent and the corresponding coupling constants are resolved.

Crystal structure of magnesium chromium vanadate Mg2CrV3O11, a member of the A2BV3O11 vanadate family

2007 ◽  
Vol 22 (3) ◽  
pp. 246-252 ◽  
Author(s):  
A. Worsztynowicz ◽  
S. M. Kaczmarek ◽  
W. Paszkowicz ◽  
R. Minikayev
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Ion Pairs ◽  
Exchange Constant ◽  
Type I ◽  
Type Ii ◽  
Paramagnetic Resonance ◽  
Interatomic Distances ◽  
Electron Paramagnetic ◽  
Full Occupancy

The crystal structure of recently discovered chromium (III) dimagnesium trivanadate (V) Mg2CrV3O11 was refined using the Rietveld method. The crystal system of Mg2CrV3O11 is triclinic with space group P1− (Mg1.7Zn0.3GaV3O11 type) and lattice parameters a=6.4057(1) Å, b=6.8111(1) Å, c=10.0640(2) Å, α=97.523(1)°, β=103.351(1)°, γ=101.750(1)°, and Z=2. The characteristic feature of compounds in the A2BV3O11 (A=Mg, Zn and B=Ga, Fe, Cr) family is a strong tendency to share the octahedral M(1) and M(2) sites by both divalent A and trivalent B atoms, and the bipyramidal M(3) sites occupied by divalent A ions. In the present refinement, the only constraint assuming full occupancy of the M(1), M(2), and M(3) sites leads to the following Cr/(Cr+Mg) ratios: 0.70(2) at M(1), 0.24(2) at M(2), and 0.03(2) at M(3). These occupancies are discussed and compared to those of isotypic compounds. The values of interatomic distances are found to be comparable with those reported by R. D. Shannon in 1976. Electron paramagnetic resonance has been also analyzed. Two absorption lines with g≈2.0 (type I) and g≈1.98 (type II) have been recorded in the EPR spectra, and attributed to V4+ ions and Cr3+–Cr3+ ion pairs, respectively. The exchange constant J between Cr3+ ions has been calculated.

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