ESR SPECTRA OF Fe+3 IN SINGLE CRYSTALS OF ANDALUSITE

ESR spectra of Fe+3 in andalusite have been investigated at X- and K-band frequencies at room temperature. They have been interpreted on the assumption that Fe+3 occupies the two inequivalent Al+3 sites in andalusite. The spectra show large zero-field splitting. The constants of the conventional orthorhombic spin Hamiltonian which fit the spectra are as follows: for site I: b20 = 15.0 ± 0.1 kG, b22 = 5.0 ± 0.1 kG, and isotropic g = 2.001 ± 0.002; for site II: b20 = 20.1 ± 0.1 kG, b22 = 0.075 ± 0.010 kG, and isotropic g = 2.004 ± 0.0005. A study of the intensities of ESR signals due to site I follow a pattern predicted by theory. The implications of these results are considered briefly.

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ELECTRON SPIN RESONANCE OF Fe+3 IN CORDIERITE

Canadian Journal of Physics ◽

10.1139/p66-223 ◽

1966 ◽

Vol 44 (11) ◽

pp. 2749-2755 ◽

Cited By ~ 6

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.

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Temperature Dependence of the Zero-Field Splitting of Cr3+ Ions in CsAl(SO4)2∙12H2O

Canadian Journal of Physics ◽

10.1139/p74-012 ◽

1974 ◽

Vol 52 (1) ◽

pp. 91-92 ◽

Cited By ~ 4

Author(s):

John A. MacKinnon ◽

G. Stevenson

Keyword(s):

Room Temperature ◽

Experimental Spectrum ◽

Zero Field ◽

Helium Temperature ◽

Spin Hamiltonian ◽

Zero Field Splitting ◽

Field Splitting ◽

A Value ◽

Zero Field Splitting Parameter ◽

Splitting Parameter

The zero-field splitting of Cr3+ ions in CsAl(SO4)2∙12H2O was studied in the temperature range 4.2 to 300 K. The experimental spectrum is described with a spin Hamiltonian with S = 3/2 and g = 1.975 ± 0.005; the zero-field splitting parameter D changes with temperature having a value of −0.074 ± 0.0003 cm−1 at room temperature and a value of −0.070 ± 0.0003 cm−1 at liquid helium temperature.

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ESR SPECTRUM OF Fe+3 IN TOPAZ: I. FINE STRUCTURE

Canadian Journal of Physics ◽

10.1139/p67-303 ◽

1967 ◽

Vol 45 (11) ◽

pp. 3597-3610 ◽

Cited By ~ 16

Author(s):

J. R. Thyer ◽

S. M. Quick ◽

F. Holuj

Keyword(s):

Fine Structure ◽

Zero Field ◽

Spin Hamiltonian ◽

Zero Field Splitting ◽

Field Splitting ◽

Esr Spectrum ◽

Hamiltonian Parameters ◽

Near Future ◽

K Band

ESR spectrum of Fe+3 in topaz (Al2SiO4F2) has been investigated at X- and K-band frequencies. The spectrum, in addition to large zero-field splitting, also shows well-resolved h.f.s. due to 19F at some orientations. The spin-Hamiltonian parameters, which include b21 and b41, are given in the text. The spectrum has been interpreted to originate from Fe+3 impurity located at Al+3 sites. The implications of these results are considered briefly. The results of the analysis of the h.f.s. are to be published in the near future.

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The EPR Zero-Field Splitting D and its Pressure and Temperature Dependence for Trigonal Mn2+ Centers in [Zn(H2O)6](BF4)2:Mn2+ Crystal

Zeitschrift für Naturforschung A ◽

10.1515/zna-2006-5-613 ◽

2006 ◽

Vol 61 (5-6) ◽

pp. 289-292 ◽

Cited By ~ 1

Author(s):

Hong-Gang Liu ◽

Xiao-Xuan Wu ◽

Wen-Chen Zheng ◽

Lv He

Keyword(s):

Temperature Dependence ◽

Room Temperature ◽

Coupling Mechanism ◽

Zero Field ◽

Spin Orbit Coupling ◽

Zero Field Splitting ◽

Field Splitting ◽

Thermal Expansion Coefficients ◽

Perturbation Formula ◽

Expansion Coefficients

The EPR zero-field splitting D (= b02 ) and its pressure and temperature dependence for trigonal Mn2+ centers in low and room temperature phases in [Zn(H2O)6](BF4)2 :Mn2+ crystal are studied by a high-order perturbation formula based on the dominant spin-orbit coupling mechanism. From the studies, the local trigonal distortion angles, the local angular compressibilities and the local angular thermal expansion coefficients for Mn2+ centers in both phases of the [Zn(H2O)6](BF4)2 crystal are estimated. The results are discussed

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EPR Study of the Nitrogen Containing Defect Center Created in Self-Assembled 6H SiC Nanostructure

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.389 ◽

2013 ◽

Vol 740-742 ◽

pp. 389-392 ◽

Cited By ~ 2

Author(s):

Ekaterina N. Kalabukhova ◽

Dariya Savchenko ◽

Bela Shanina ◽

Nikolai T. Bagraev ◽

Leonid Klyachkin ◽

...

Keyword(s):

The Self ◽

Zero Field ◽

Boron Diffusion ◽

Spin Hamiltonian ◽

Zero Field Splitting ◽

Epr Spectrum ◽

Defect Center ◽

Field Splitting ◽

Splitting Constant ◽

Self Assembled

Triplet center with spin state S = 1 is detected in the EPR spectrum of the self-assembled 6H SiC nanostructure obtained by non-equilibrium boron diffusion into the n-type 6H SiC epitaxial layer (EL) under conditions of the controlled injection of the silicon vacancies at the temperature of T = 900°C. From the analysis of the angular dependences of the EPR spectrum and the numerical diagonalization of the spin Hamiltonian, the value of the zero-field splitting constant D and g-factor are found to be D = 1140•10-4см-1 and gpar = 1.9700, gper = 1.9964. Based on the hyperfine (hf) structure of the defect originating from the hf interaction with one 14N nuclei, the large value of the zero-field splitting constant D and technological conditions of the boron diffusion into the n-type 6H SiC EL, the triplet center is tentatively assigned to the defect center consisting of nitrogen atom and silicon vacancy.

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Fine Structure of Triplet Centers in Room Temperature Irradiated 6H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.645-648.403 ◽

2010 ◽

Vol 645-648 ◽

pp. 403-406 ◽

Cited By ~ 3

Author(s):

Andreas Scholle ◽

Siegmund Greulich-Weber ◽

Eva Rauls ◽

Wolf Gero Schmidt ◽

Uwe Gerstmann

Keyword(s):

Fine Structure ◽

Room Temperature ◽

Positive Sign ◽

Spin Interaction ◽

Zero Field ◽

Spin Orbit ◽

Zero Field Splitting ◽

Defect Center ◽

Field Splitting ◽

Annealing Behavior

In non-annealed 6H-SiC samples that were electron irradiated at room temperature, a new EPR signal due to a S=1 defect center with exceptionally large zero-field splitting (D = +652•10-4 cm-1) has been observed under illumination. A positive sign of D demonstrates that the spin-orbit contribution to the zero-field splitting exceeds by far that of the spin-spin interaction. A principal axis of the fine structure tilted by 59° against the crystal c-axis as well as the exceptionally high zero-field splitting D can be qualitatively understood by the occurrence of additional close-lying defect levels in defect clusters resulting in comparatively large second-order spin-orbit coup¬ling. A tentative assignment to vacancy clusters is supported by the observed annealing behavior.

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