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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:22 |
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Conference: Bucharest University Faculty of Physics 2002 Meeting
Section: Atomic and Molecular Physics; Astrophysics
Title:
Analysis of Mn2+ EPR Spectra in Natural Carbonates
Authors:
D. Scliros , V. V. Grecu, O. G. Duliu
Affiliation:
Physics Faculty, University of Bucharest
E-mail
Keywords:
Abstract:
Manganese is a common impurity in carbonates and other oxide natural materials. As these samples are usually polycrystalline the identification of the carbonates nature is difficult. Only measuring very accurately the g-factor and the hyperfine constant can do it. A more promising way is to use the hyperfine forbidden lines. These lines come from mixed terms of fine structure and the hyperfine interactions. The case of Mn2+ ions is very favorable for such an approach as the fine term is large enough for producing strong forbidden lines, but significantly smaller than the Zeeman term, In such conditions perturbation theory can be used [1-3]
EPR spectra of several carbonates, mainly marbles, from different regions of Greece have been measured. The spectra are quite different depending on the marble composition. Two main carbonates have been identified, calcite and dolomite. The spectra are analyzed by using a fitting procedure, based on a perturbation method for solving the spin hamiltonian. The relative contributions of different phases will be given together with the spin-hamiltonian parameters. The fitting procedure will be described. The results will be discussed in comparison with X-ray diffraction data.
References.
[1] I. Ursu, Resonance Electronique Paramagnetique, Dunod, Paris, 1960
[2] V. Lupei, A. Lupei, F. Domsa, J. Mag. Resonance, 19 (1975) 337
[3] S. K. Misra, G. C. Upreti, Mag. Res. Review, 12 (1987) 1-34
Scliros, D- Ph.D. student
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