Electron Paramagnetic Resonance of Ti3+ Ions in KAl(SO4)2∙12H2O

1975 ◽  
Vol 53 (8) ◽  
pp. 841-842 ◽  
Author(s):  
John A. MacKinnon ◽  
M. Shannon

The paramagnetic resonance spectrum of Ti3+ ions in potassium alum (KAl(SO4)2∙12H2O) single crystals has been studied in the {100} planes at 4.2 K with an X band microwave spectrometer. The spectrum is an analogue of that reported by Dionne for Ti3+ ions in rubidium alum (RbAl(SO4)2∙12H2O) and by MacKinnon and Dionne for Ti3+ ions in the thallium alum (TlAl(SO4)2∙12H2O). The spectrum was explained with a model of 12 magnetic complexes, the complexes being related to each other through the symmetry elements of the [Formula: see text] point group of the alum lattice. The three g factors for the spin Hamiltonian with S = 1/2 were found to be 1.979, 1.898, and 1.828, with an accuracy of ±0.005.

1964 ◽  
Vol 42 (12) ◽  
pp. 2419-2428 ◽  
Author(s):  
Gerald F. Dionne

The paramagnetic resonance spectrum of the Ti3+ ion in cubic RbAl(SO4)2 ∙ 12H2O single crystals has been studied in the {100} and {110} planes at 4.2 °K with an X-band microwave spectrometer. The spectrum, which consists of a maximum of 12 lines, has been explained by considering a model of 12 magnetic complexes which are related to each other through the symmetry elements of the Th = (2/m)3 point group of the Rb alum lattice. For the spin Hamiltonian with [Formula: see text], three g factors have been determined—1.895, 1.715, and 1.767— within an accuracy of ±0.002, indicating the existence of a crystal electric field of orthorhombic symmetry.


1971 ◽  
Vol 49 (11) ◽  
pp. 1539-1541 ◽  
Author(s):  
J. G. Clarke ◽  
J. A. MacKinnon

The electron paramagnetic resonance spectrum of the V3+ ion in CsAl(SO4)2∙12H2O single crystals has been studied in the {100} and {111} planes at 4.2 °K with an X-band microwave spectrometer.


2006 ◽  
Vol 61 (12) ◽  
pp. 683-687 ◽  
Author(s):  
Ram Kripal ◽  
Ashutosh Kumar Shukla

Electron paramagnetic resonance (EPR) studies of Mn2+ impurity in single crystals of diammonium hexaaqua magnesium(II) sulfate have been carried out at 9.3 GHz (X-band) at room temperature. The EPR spectra exhibit a group of five fine structure transitions. The spin-Hamiltonian parameters were determined. Mn2+ enters the lattice interstitially. The EPR spectrum of a powder sample supports the data obtained by single crystal studies. - PACS number: 76.30


1982 ◽  
Vol 37 (9) ◽  
pp. 1092-1093 ◽  
Author(s):  
Mohd. Waseem ◽  
R. Dayal ◽  
Vimal Kumar Jain

Abstract The electron paramagnetic resonance of Cu2+ in ferroelectric LiH3(SeO3)2 has been studied at 298 K in X-band. The Cu2+ appears to substitute Li+ in the lattice with the z-axis nearly along the Li-O(6) bond direction. The spectra have been analysed using the spin-Hamiltonian appropriate for Cu2+ in orthorhombic symmetry.


1996 ◽  
Vol 51 (4) ◽  
pp. 245-248
Author(s):  
Geetha Jayaram ◽  
V. G. Krishnan

Abstract Electron Paramagnetic Resonance (EPR) studies have been carried out on the vanadyl (VO2) ion doped in single crystals of ZnTiF6 • 6H2O. The spectra indicate the presence of one set of eight lines characteristic of only one occupation site. The V-O bond orientation is along one of the three Zn-H2O bond directions in the trigonally distorted [Zn(H2O)6] octahedra. This behaviour is unlike that reported for vanadyl ion substituting for the M(H2O)6 sites in the Tutton salts, alums and AlCl3 • 6H2O. The Spin-Hamiltonian and bonding parameters for the [VO(H2O)5] complex have been evaluated. The hyperfine linewidths are 0.8 mT at 300 K and 77 K. No proton superhyperfine structure was observed at both these temperatures.


1980 ◽  
Vol 3 ◽  
Author(s):  
Sushil K. Misra ◽  
M. Jalochowski

ABSTRACTThe technique of electron paramagnetic resonance has been applied to study the magnetic properties of nickel acetate and nickel potassium tutton salt single crystals, using Mn2+ ion as probe. From the values of spin Hamiltonian parameters and linewidths at room, liquid nitrogen and liquid helium temperatures it is concluded that these crystals do not become magnetically ordered as the temperature is lowered to 3.2K, and thus the transition temperature, below which the crystal would order either ferromagnetically, or antiferromagnetically, for these crystals, should be below 3.2K.


1997 ◽  
Vol 52 (12) ◽  
pp. 849-854 ◽  
Author(s):  
Metin Yavuz ◽  
Hüseyin Kalkan ◽  
Ahmet Bulut ◽  
Şehriman Atalay ◽  
Emin Öztekin

The results of an electron paramagnetic resonance (EPR) study of vanadyl ion VO2+ doped in single crystals of Ba(ClO4)2 - 3 H2O are reported. The spectra indicated the presence of two substitutional and interstitial sites depending on the orientation. The spin-Hamiltonian parameters were determined from single crystal and powder EPR data. These parameters were found to be axial symmetric for the powder sample, whereas they showed deviations from axial symmetry for the single crystal


2019 ◽  
Vol 5 (10) ◽  
pp. eaay1394 ◽  
Author(s):  
Jason W. Sidabras ◽  
Jifu Duan ◽  
Martin Winkler ◽  
Thomas Happe ◽  
Rana Hussein ◽  
...  

Electron paramagnetic resonance (EPR) spectroscopy on protein single crystals is the ultimate method for determining the electronic structure of paramagnetic intermediates at the active site of an enzyme and relating the magnetic tensor to a molecular structure. However, crystals of dimensions typical for protein crystallography (0.05 to 0.3mm) provide insufficient signal intensity. In this work, we present a microwave self-resonant microhelix for nanoliter samples that can be implemented in a commercial X-band (9.5 GHz) EPR spectrometer. The self-resonant microhelix provides a measured signal-to-noise improvement up to a factor of 28 with respect to commercial EPR resonators. This work opens up the possibility to use advanced EPR techniques for studying protein single crystals of dimensions typical for x-ray crystallography. The technique is demonstrated by EPR experiments on single crystal [FeFe]-hydrogenase (Clostridium pasteurianum; CpI) with dimensions of 0.3 mm by 0.1 mm by 0.1 mm, yielding a proposed g-tensor orientation of the Hox state.


2004 ◽  
Vol 59 (1-2) ◽  
pp. 103-104 ◽  
Author(s):  
Biray Aşik ◽  
Mehmet Birey

The electron paramagnetic resonance of γ -Irradiated single crystals of dimethyl malonic acid [(CH3)2C(COOH)2] has been studied for different orientations of the crystal in a magnetic field. The radicals produced by gamma irradiation have been investigated between 123 and 300 K. The spectra were found to be temperature independent, and radiation damage centres were attributed to [(CH3)2C(COOH)2]+ radicals. The g factor and hyperfine coupling constants were found to be almost isotropic with average values g = 2.0036, a(COOH)2 = 0.5 mT, a(CH3)2 = 2.1 mT, respectively, and spin density ρ = 91% of the [(CH3)2C(COOH)2]+ radical.


1998 ◽  
Vol 53 (9) ◽  
pp. 779-782
Author(s):  
F. Köksal ◽  
İ. Kartal ◽  
A. Gençten

Abstract The electron paramagnetic resonance spectra of Cu2+ doped Na2HAsO4 ·7H2O single crystals were studied at room temperature. The results indicate the substitutional entrance of Cu2+ in two magnetically inequivalent Na+ sites. Charge compensation is supposed to be fulfilled by proton vacancies. The spin Hamiltonian parameters were determined. The ground state for Cu2+ seems to indicate the dominance of the dz² orbital and therefore a compression of the distorted octahedron along its C4v axis.


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