EPR of Gd3+ in Sulfate Host Crystals of Low Symmetry

1997 ◽  
Vol 52 (4) ◽  
pp. 323-330
Author(s):  
M. Bode ◽  
B. D. Mosel ◽  
W. Müller-Warmuth
Keyword(s):  
Metal Ion ◽  
Charge Compensation ◽  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Spin Quantum ◽  
Spin Quantum Number ◽  
Host Metal ◽  
Low Symmetry

Abstract Electron paramagnetic resonance (EPR) spectra of trivalent gadolinium have been investigated in orthorhombic sulfate host crystals MeSO4 with Me = Sr, Ba, Cd, Hg, Pb and K2SO4 . Because of the low symmetry of the host crystals and the spin quantum number 7/2, complex spectra for several orientations of the magnetic field containing a large number of individual lines had to be analyzed. The spin Hamiltonian parameters have been rigorously determined from the rotational diagrams. Gd3+ has been found to substitute, first of all, for the monoclinic sites of the host metal ion with charge compensation at larger distances. To a small extent, charge compensation in the vicinity has also been observed, arising from additional centres and spectra with lower intensities. Correlations between EPR spectra and crystal structure are reflected in the values of the zero field splitting parameters.

EPR Studies of Cr3+ and Fe3+ in Host Crystals with Langbeinite Structure

1996 ◽  
Vol 51 (10-11) ◽  
pp. 1123-1133
Author(s):  
J. Kastner ◽  
B. D. Mosel ◽  
W. Müller-Warmuth
Keyword(s):  
Charge Compensation ◽  
Qualitative Description ◽  
Ligand Field ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Local Relaxation ◽  
Hamiltonian Parameters ◽  
Electron Paramagnetic

Abstract Electron paramagnetic resonance (EPR) spectra of trivalent chromium and iron ions have been investigated in host crystals of double sulfates with langbeinite structure, A2B2(SO4)3 , with A = NH4+, Rb+, Tl+ and B = Cd2+, Mg2+. In most cases, single crystals could be grown, and the spin Hamiltonian parameters have been determined from the rotational diagrams. Powder spectra were analyzed and simulated as well. Three centres of axial symmetry with different zero field splittings have been observed for Cr3+, and two for Fe3+. The trivalent impurity ions have been shown to occupy divalent lattice sites substitutionally, but the environments are different depending on the structure and the mechanism of charge compensation. A qualitative description of the incorporation of dopants has been possible on this basis, taking into account the local relaxation and the ligand field stabilization effects. Temperature dependent single crystal and powder measurements have provided information on the zero field splitting and phase transitions.

Substituent effects on the triplet–singlet energy separation in diphenylmethylene

1977 ◽  
Vol 55 (12) ◽  
pp. 2286-2291 ◽  
Author(s):  
Robert W. R. Humphreys ◽  
Donald R. Arnold
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Ground State ◽  
Signal Intensity ◽  
Substituent Effects ◽  
Epr Spectra ◽  
Energy Separation ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The electron paramagnetic resonance (epr) spectra of the diarylmethylenes: diphenylmethylene, p-cyanodiphenylmethylene, p-methoxydiphenylmethylene, p,p′-dimethoxydiphenylmethylene, p,p′-dicyanodiphenylmethylene, p-cyano-p′-methoxydiphenylmethylene, have been studied. The zero-field splitting parameters have been determined. The signal intensity as a function of temperature (ca. 4–20 K) indicates these methylenes are ground state triplet species.

scholarly journals Readout and control of an endofullerene electronic spin

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dinesh Pinto ◽  
Domenico Paone ◽  
Bastian Kern ◽  
Tim Dierker ◽  
René Wieczorek ◽  
...  
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
Dipolar Interaction ◽  
Nitrogen Vacancy ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Near Surface ◽  
Atomic Spins ◽  
And Control

AbstractAtomic spins for quantum technologies need to be individually addressed and positioned with nanoscale precision. C60 fullerene cages offer a robust packaging for atomic spins, while allowing in-situ physical positioning at the nanoscale. However, achieving single-spin level readout and control of endofullerenes has so far remained elusive. In this work, we demonstrate electron paramagnetic resonance on an encapsulated nitrogen spin (14N@C60) within a C60 matrix using a single near-surface nitrogen vacancy (NV) center in diamond at 4.7 K. Exploiting the strong magnetic dipolar interaction between the NV and endofullerene electronic spins, we demonstrate radio-frequency pulse controlled Rabi oscillations and measure spin-echos on an encapsulated spin. Modeling the results using second-order perturbation theory reveals an enhanced hyperfine interaction and zero-field splitting, possibly caused by surface adsorption on diamond. These results demonstrate the first step towards controlling single endofullerenes, and possibly building large-scale endofullerene quantum machines, which can be scaled using standard positioning or self-assembly methods.

Zur paramagnetischen Elektronenresonanz metallorganischer Sandwich-Verbindungen, Teil I / The magnetic resonance properties of some sandwich compounds, part i

1972 ◽  
Vol 27 (7) ◽  
pp. 1082-1093
Author(s):  
R Krieger ◽  
J Voitländer
Keyword(s):  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Degenerate Ground State ◽  
Resonance Properties ◽  
Rhombic Distortion ◽  
Combined Action ◽  
Low Symmetry

AbstractThe zero-field splitting and g-values of manganocene and chromocene have been calculated. The wave functions were obtained by means of a self-consistent charge extended Huckel method. The calculated values g||=2.0034 and g⊥ = 2.0033 of manganocene agree fairly well with the experi­mental results obtained from ESR measurements. The very large computed zero-field splitting D= -0.24 cm-1 explains that there has been observed only one ESR transition though mangano­cene is in a spin-5/2 state. For chromocene no ESR transition has been found until now. We therefore studied the splitting of the orbitally degenerate ground state by the combined action of spin-orbit coupling and low-symmetry perturbation. The predicted splitting is strongly dependent on the magnitude of the rhombic distortion compared to the spin-orbit interaction. The g-values are highly anisotropic, with g|| =2.49 and g⊥ =1.97

EPR spectra and zero-field splitting of exchange-coupled copper(II)-manganese(II) pairs

1981 ◽  
Vol 20 (8) ◽  
pp. 2734-2735 ◽  
Author(s):  
L. Banci ◽  
A. Bencini ◽  
D. Gatteschi
Keyword(s):  
Epr Spectra ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting

Synthesis and Characterization of the Heptanuclear [MnIII 6 CoIII]3+ Triplesalen Complex: Evidence for Exchange Pathways Involving Low-spin CoIII

2010 ◽  
Vol 65 (3) ◽  
pp. 295-303 ◽  
Author(s):  
Erich Krickemeyer ◽  
Veronika Hoeke ◽  
Anja Stammler ◽  
Jürgen Schnack ◽  
Hartmut Bögge ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Metal Ion ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
Molecular Structures ◽  
Magnetic Data ◽  
Zero Field ◽  
Central Metal ◽  
Zero Field Splitting ◽  
Isotropic Exchange

The reaction of the tert-butyl-substituted triplesalen ligand H6talent-Bu2 with MnII(OAc)2・ 4H2O and K3[CoIII(CN)6] results in the formation of the heptanuclear complex [{(talent-Bu2 )- (MnIII(MeOH))3}2{CoIII(CN)6}](PF6)2(OAc)・11MeOH ([MnIII6 CoIII](PF6)2(OAc)・11MeOH, 1 ・11MeOH), which has been characterized by FT-IR spectroscopy, elemental analysis, ESI-MS, single-crystal X-ray diffraction, and magnetic measurements. The molecular structure of the [MnIII6 CoIII]3+ complex is closely related to the already published analogs [MnIII6CrIII]3+ and [MnIII6 FeIII]3+. Variable-temperature variable-field and μeff vs. T magnetic data have been analyzed in detail by full-matrix diagonalization of the appropriate spin-Hamiltonian consisting of isotropic exchange, zero-field splitting, and Zeeman interaction, taking into account the relative orientation of the D tensors. This allowed a careful inspection of the MnIII-MnIII exchange interaction involving a diamagnetic central metal ion. A satisfactory reproduction of the magnetic data required the incorporation not only of an exchange interaction between the MnIII ions belonging to one triplesalen half unit, but also of an exchange coupling between MnIII ions belonging to different triplesalen subunits. Satisfactory reproduction of the experimental data has been obtained for the parameter set J1 = −(0.50±0.04) cm−1, J2 = +(0.05±0.02) cm−1, and D = −(2.5±0.5) cm−1. A detailed analysis of the J1 coupling taking into account the molecular structures of the three available heptanuclear complexes [MnIII6MIII]3+ (M = Cr, Fe, Co) indicates that the exchange interaction between the MnIII ions belonging to the same triplesalen subunit involves not only an exchange pathway through the central phloroglucinol unit but also an exchange pathway through the central metal ion.

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