EPR spectra and linewidths of Mn2+ in calcite
The constants corresponding to the spin-Hamiltonian terms without cylindrical symmetry for Mn2+ in calcite (CaCO3) have been measured by EPR techniques; it is shown that the principal axes of the spin Hamiltonian are rotated 15.5°from the crystal axes. This value allows us to obtain information abou...
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Autores principales: | , , , |
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Formato: | JOUR |
Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_01631829_v12_n3_p853_Barberis |
Aporte de: |
Sumario: | The constants corresponding to the spin-Hamiltonian terms without cylindrical symmetry for Mn2+ in calcite (CaCO3) have been measured by EPR techniques; it is shown that the principal axes of the spin Hamiltonian are rotated 15.5°from the crystal axes. This value allows us to obtain information about the charge distribution of the carbonate ligands. Our result is in agreement with the predictions of a simple covalent model for the carbonates. We measured also the angular variation of the linewidth of an EPR transition; our data allow us to explain the source of the inhomogeneous broadening for Mn2+ in our sample as random internal stresses. We compare our results with previous data obtained for Mn2+ in CaWO4 where the source of broadening is a distribution of point defects in the sample. A method for finding the source of inhomogeneous broadening in sites of low symmetry is discussed. © 1975 The American Physical Society. |
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