A Microwave Frequency Marginal Oscillator for Electron Spin Resonance

1970 ◽  
Vol 41 (9) ◽  
pp. 1316-1318 ◽  
Author(s):  
W. M. Walsh ◽  
L. W. Rupp
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Microwave Frequency ◽  
Spin Resonance

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.

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.

scholarly journals Electron Spin Resonance Properties of CrI3 and CrCl3 Single Crystals

MRS Advances ◽  
2019 ◽  
Vol 4 (40) ◽  
pp. 2169-2175 ◽  
Author(s):  
C. L. Saiz ◽  
M. A. McGuire ◽  
S. R. J. Hennadige ◽  
J. van Tol ◽  
S. R. Singamaneni
Keyword(s):  
Electron Spin Resonance ◽  
Single Crystals ◽  
Electron Spin ◽  
Microwave Frequency ◽  
Magnetic Interactions ◽  
Resonance Spectroscopy ◽  
Spin Resonance ◽  
Temperature Dependences ◽  
Bulk Single Crystals ◽  
Underlying Mechanisms

ABSTRACTDeveloping functional, cleavable two-dimensional materials for use in next generation devices has recently become a topic of considerable interest due to their unique properties. Of particular interest, transition metal halides CrI3 and CrCl3 have shown to be good contenders for tunable and cleavable magnetic materials due to their unique magnetic properties in the monolayer. Here, electron spin resonance spectroscopy is used to pinpoint the atomic origins and underlying mechanisms of magnetic interactions as a function of temperature (5-500 K) and microwave frequency (9.43, 120 GHz) on CrI3 and CrCl3 bulk single crystals. ESR signals from CrI3 due to Cr3+ were observed to decay at 460 K, while ESR signals from CrCl3 remain up to 500 K. In the case of CrCl3, the temperature dependences of signal behavior, line width and g-value show characteristic signatures of ferromagnetic fluctuations at around 40 K, near to the antiferromagnetic phase transition at 17 K.

Electron spin resonance of Mn2+ impurities in monticellite

1969 ◽  
Vol 47 (8) ◽  
pp. 839-846 ◽  
Author(s):  
A. G. Danilov ◽  
A. Manoogian
Keyword(s):  
Electron Spin Resonance ◽  
Electric Fields ◽  
Electron Spin ◽  
Microwave Frequency ◽  
Spectral Lines ◽  
Orthorhombic Symmetry ◽  
Principal Axes ◽  
Spin Resonance ◽  
Crystalline Electric Fields ◽  
Crystallographic Axes

The electron spin resonance of Mn2+ impurity ions in natural crystals of monticellite, MgCaSiO4, was studied in the 9.4 GHz and 35 GHz microwave frequency ranges, and at room temperature. Four magnetic complexes of manganese were observed, and these were found to degenerate into two in the (010) crystallographic plane. The magnetic field separations of the spectral lines along the principal axes of the crystalline electric fields were the same for all four complexes. The resonance lines were fitted to a spin Hamiltonian of orthorhombic symmetry, and the following parameters were determined: gz = 1.9961, gy = 1.9905, b20 = −558.5, b22 = −351.7, b40 = −0.5, b42 = −56.0, b44 = −40.3, A = 85.5, B = 85.5. The values of bnm, A, and B are in gauss, and the signs are relative. It was possible to relate the axes of the Mn2+ magnetic complexes to the crystallographic axes. Hence, it was determined that the Mn2+ ions replace Mg2+ ions, which are in centers with inversion symmetry, and not Ca2+ ions, which are in centers containing a reflection plane.

Intensity of allowed and forbidden electron spin resonance lines of Mn2+ in tremolite

1968 ◽  
Vol 46 (9) ◽  
pp. 1029-1033 ◽  
Author(s):  
A. Manoogian
Keyword(s):  
Electron Spin Resonance ◽  
Electric Fields ◽  
Electron Spin ◽  
Theoretical Calculations ◽  
Microwave Frequency ◽  
Orthorhombic Symmetry ◽  
Crystalline Electric Field ◽  
Line Intensities ◽  
Spin Resonance ◽  
Crystalline Electric Fields

The angular variation of the intensities of the allowed and forbidden (Δm = ±1) electron spin resonance lines of Mn2+ impurities in tremolite, 2(H2Ca2Mg5(SiO3)8), was studied at room temperature and in the 9.2-GHz microwave frequency range. The crystalline electric field for the magnetic complex of Mn2+ in tremolite has orthorhombic symmetry, and this causes the line intensities to vary asymmetrically between the z and y magnetic axes. The experimental measurement of these intensities is in good agreement with the theoretical calculations of Bir (1964). Bir's theory has been used with success previously by others for ions in the higher-symmetry axial and cubic crystalline electric fields.

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.

Coherent Raman detected electron spin resonance spectroscopy of metalloproteins: linking electron spin resonance and magnetic circular dichroism

2008 ◽  
Vol 36 (6) ◽  
pp. 1187-1190 ◽  
Author(s):  
Stephen J. Bingham ◽  
Daniel Wolverson ◽  
Andrew J. Thomson
Keyword(s):  
Circular Dichroism ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Metal Ion ◽  
Magnetic Circular Dichroism ◽  
Microwave Frequency ◽  
Resonance Spectroscopy ◽  
Spin Resonance ◽  
Coherent Raman ◽  
Circular Dichroïsm

The simultaneous excitation of paramagnetic molecules with optical (laser) and microwave radiation in the presence of a magnetic field can cause an amplitude, or phase, modulation of the transmitted light at the microwave frequency. The detection of this modulation indicates the presence of coupled optical and ESR transitions. The phenomenon can be viewed as a coherent Raman effect or, in most cases, as a microwave frequency modulation of the magnetic circular dichroism by the precessing magnetization. By allowing the optical and magnetic properties of a transition metal ion centre to be correlated, it becomes possible to deconvolute the overlapping optical or ESR spectra of multiple centres in a protein or of multiple chemical forms of a particular centre. The same correlation capability also allows the relative orientation of the magnetic and optical anisotropies of each species to be measured, even when the species cannot be obtained in a crystalline form. Such measurements provide constraints on electronic structure calculations. The capabilities of the method are illustrated by data from the dimeric mixed-valence CuA centre of nitrous oxide reductase (N2OR) from Paracoccus pantotrophus.

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