THE ELECTRON SPIN RESONANCE OF VO2+ IONS IN TWO TYPES OF ALUMINIUM ALUMS

1967 ◽  
Vol 45 (8) ◽  
pp. 2769-2777 ◽  
Author(s):  
A. Manoogian ◽  
J. A. MacKinnon
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Resonance Spectrum ◽  
Microwave Frequency ◽  
Spin Hamiltonian ◽  
Vanadyl Ion ◽  
Spin Resonance ◽  
Hamiltonian Parameters ◽  
Crystallographic Axes

The electron spin resonance spectrum of the vanadyl ion VO2+ is studied in single crystals of RbAl(SO4)2.12 H2O and CsAl(SO4)2.12 H2O, at room temperature and in the 9.2 kMc/s microwave frequency range. In RbAl(SO4)2.12 H2O the V–O axes are found to have three orientations directed along the cubic crystallographic axes, giving rise to three magnetic complexes. The spin Hamiltonian parameters are S = 1/2, [Formula: see text], [Formula: see text], [Formula: see text] cm−1, and [Formula: see text] cm−1. In CsAl(SO4)2.12 H2O the V–O axes are displaced from the crystallographic axes, giving rise to 12 magnetic complexes. The spin Hamiltonian parameters are S = 1/2, [Formula: see text], [Formula: see text], [Formula: see text] cm−1, and [Formula: see text] cm−1. The observed spectra are attributed to a vanadyl pentahydrate complex (VO2+.5 H2O) associated with a water-molecule vacancy.

The electron spin resonance of Mn2+ in tremolite

1968 ◽  
Vol 46 (2) ◽  
pp. 129-133 ◽  
Author(s):  
A. Manoogian
Keyword(s):  
Electron Spin Resonance ◽  
Angular Dependence ◽  
Electron Spin ◽  
Room Temperature ◽  
Microwave Frequency ◽  
Orthorhombic Symmetry ◽  
Spin Hamiltonian ◽  
Frequency Range ◽  
Line Intensities ◽  
Spin Resonance

The electron spin resonance of Mn2+ ion impurities in natural crystals of tremolite, 2(H2Ca2Mg5-(SiO3)8), was studied in the 9.2 GHz microwave frequency range, and at room temperature. The work was done on two crystals of tremolite containing different concentrations of Mn2+. In each case only one magnetic complex of Mn2+ was found. The resonance lines are characterized by a strong angular dependence of the line intensities, and this is coupled with the appearance of many forbidden lines of Mn2+. The resonance lines of the allowed transitions were fitted to a spin Hamiltonian of orthorhombic symmetry.

Electron spin resonance of Mn2+ impurities in morinite

1969 ◽  
Vol 47 (17) ◽  
pp. 1869-1875 ◽  
Author(s):  
A. Manoogian ◽  
Y. Hsu
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Microwave Frequency ◽  
Heat Treating ◽  
Orthorhombic Symmetry ◽  
Spin Hamiltonian ◽  
Frequency Range ◽  
Spin Resonance ◽  
Impurity Ions

The electron spin resonance of Mn2+ impurity ions in natural crystals of morinite, Ca4Na2Al4(F, OH)10(PO4)4∙3H2O, was studied in the 9.4 GHz microwave frequency range and at room temperature. A single magnetic complex was found and the resonance lines were characterized by strong splittings due to superhyperfine interactions with ligand nuclei. The resonance lines were fitted to a spin Hamiltonian of orthorhombic symmetry and the following parameters were determined: gz = 2.0014 ± 0.0005, gy = 2.0017 ± 0.0010, b2°= 166.8 ± 1.5, b22 = 69.1 ± 1.5, b40 = −0.17 ± 0.10, A = 98.2 ± 1.0, and B = C = 99.7 ± 1.5. The values of bnm, A, B, and C are in gauss, and the signs are relative. By heat-treating powdered samples of morinite to a temperature greater than 400 °C, it was shown that the morinite changed to apatite, 2[Ca5(PO4)3(F, OH)].

scholarly journals Ferromagnetic Resonance Characterization of Nano-FePt by Electron Spin Resonance

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. S. Nkosi ◽  
H. M. Gavi ◽  
D. E. Motaung ◽  
J. Keartland ◽  
E. Sideras-Haddad ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Data Storage ◽  
Ferromagnetic Resonance ◽  
Electron Spin ◽  
Iron Content ◽  
Room Temperature ◽  
Large Data ◽  
Microwave Frequency ◽  
Homogeneous Distribution ◽  
Spin Resonance

Electron spin resonance (ESR) measurements at room temperature and X-band microwave frequency were performed on highly crystalline FePt system thin films. Fairly high DC static magnetic field absorption of about 300 mT was observed in these films. We attribute the high field absorption to ferromagnetic resonance (FMR). Upon increasing iron content in FePt system, no detectable spin waves modes were identified already at room temperature. This signifies a homogeneous distribution of the magnetization across the films. We qualitatively attributed such homogeneity distribution in the films to self-assembly of these Fe–Pt system nanoparticles. The results revealed that the FePt system contains hyperfine coupling with sextetI=5/2exhibiting a phase reversal behaviour compared to FMR line. Both iron content and crystallite size increased the FMR intensity making the films good candidates for large data storage mediums and spintronics.

Temperature Dependence of the Crystal-Field Splittings in Gd3+:CaWO4

1971 ◽  
Vol 49 (8) ◽  
pp. 995-1003 ◽  
Author(s):  
J. S. M. Harvey ◽  
H. Kiefte
Keyword(s):  
Electron Spin Resonance ◽  
Low Temperature ◽  
Crystal Field ◽  
Electron Spin ◽  
Fourth Order ◽  
Lattice Vibrations ◽  
Spin Hamiltonian ◽  
Spin Resonance ◽  
Crystal Field Parameters ◽  
Hamiltonian Parameters

The spin-Hamiltonian parameters for Gd3+ in CaWO4 have been measured by the method of electron spin resonance at a number of temperatures between 4.2 °K and 300 °K. The results at 78 °K are in agreement with previous measurements by Hempstead and Bowers.The variations in the crystal-field parameters are interpreted in terms of a limiting low temperature value and a normalized slope at the Debye temperature for each parameter. These quantities are compared with the corresponding quantities for Eu2+ in CaWO4 and, in the case of the fourth-order parameters, for Eu2+ and Gd3+ in cubic CaF2, SrF2, and BaF2. We conclude that the second- and fourth-order splittings each arise from at least three competing mechanisms and that these include a dependence on the amplitude of lattice vibrations. In the case of the trivalent ion, Coulomb forces are also considered to be important.

Electron Spin Resonance of γ-Irradiated Acetylacetone in Adamantane Matrix

1972 ◽  
Vol 50 (7) ◽  
pp. 1096-1098 ◽  
Author(s):  
W. H. Wolodarsky ◽  
J. K. S. Wan
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin Resonance Spectrum ◽  
Electron Spin ◽  
Room Temperature ◽  
Resonance Spectrum ◽  
Spin Resonance ◽  
Allylic Radical

Electron spin resonance spectrum is observed when samples of solid adamantane doped with acetylacetone are γ-irradiated at room temperature. The spectrum is interpreted due to an enolized allylic radical CH3-COCHC(OH)CH2.

ELECTRON SPIN RESONANCE OF Fe+3 IN CORDIERITE

1966 ◽  
Vol 44 (11) ◽  
pp. 2749-2755 ◽  
Author(s):  
N. E. Hedgecock ◽  
S. C. Chakravartty
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Room Temperature ◽  
Esr Spectra ◽  
Orthorhombic Symmetry ◽  
Zero Field ◽  
Spin Hamiltonian ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Spin Resonance

ESR spectra of Fe+3 located at one of the aluminium sites in cordierite have been investigated at X- and K-band frequencies at room temperature. The spectra exhibit large zero-field splitting and have been fitted to a spin Hamiltonian of orthorhombic symmetry, having constants b20 = 14.6 ± 0.1 kG, b22 = 8.5 ± 0.1 kG, and isotropic g = 2.004 ± 0.002.

Electron spin resonance of Mn2+ in Cd2V2O7

1968 ◽  
Vol 46 (7) ◽  
pp. 807-810 ◽  
Author(s):  
Carl V. Stager
Keyword(s):  
Electron Spin Resonance ◽  
Single Crystals ◽  
Electron Spin ◽  
Point Charge ◽  
Reasonable Agreement ◽  
Spin Hamiltonian ◽  
Point Charge Model ◽  
Charge Model ◽  
Spin Resonance ◽  
Hamiltonian Parameters

The electron spin resonance of Mn2+ impurities has been investigated in single crystals of Cd2V2O7. The spin-Hamiltonian parameters are gx = 2.0004(8), gy = 1.9995(8), gz = 2.0001(8), b20 = −419(1)g, b22 = 125(2)g, Ax = −86.7(3)g, Ay = −87.0(10)g, and Az = −87.4(5)g. The results have been compared with similar studies on isomorphic crystals and with a calculation employing the point-charge model for the crystal field. The model gives reasonable agreement with the experimental results.

AN ELECTRON SPIN RESONANCE STUDY OF MANGANESE IMPURITY IN BRUCITE

1961 ◽  
Vol 39 (1) ◽  
pp. 145-157 ◽  
Author(s):  
W. A. Pieczonka ◽  
H. E. Petch ◽  
A. B. McLay
Keyword(s):  
Absorption Spectrum ◽  
Electron Spin Resonance ◽  
Single Crystal ◽  
Electron Spin ◽  
Room Temperature ◽  
Electron Spin Resonance Study ◽  
Spin Hamiltonian ◽  
Air Temperatures ◽  
Spin Resonance ◽  
Spin Resonance Study

A single crystal of brucite, Mg(OH)2, containing manganese impurity to the extent of 100 parts per million, has been studied by means of the electron spin resonance (esr) technique. The study was made at room and liquid air temperatures. The observed absorption spectrum has been successfully interpreted in terms of parameters found in the appropriate spin-Hamiltonian. The measured values of these parameters at room temperature were found to be:[Formula: see text]

Sign in / Sign up

Export Citation Format

Share Document