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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:40 |
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Conference: Bucharest University Faculty of Physics 2002 Meeting
Section: Solid State Physics and Materials Science
Title:
57Fe-Nuclear resonance investigations of some natural granats: X++3Y+++2Si3O12(X++=Ca,Fe,Mg,Mn;Y+++=Al,Cr,Fe)
Authors:
S. Constantinescu*, Gh. Udubasa**, M. Preda***, M.R. Leonovici***
Affiliation:
*INCDFM, **Geological Institute of Roumania, ***University of Bucharest, Faculty of Physics
E-mail
Keywords:
Abstract:
Some natural granats of serie X++3Y+++2Si3O12(X++=Ca,Fe,Mg,Mn;Y+++=Al,Cr,Fe) were
caracterized by 57Fe Mossbauer spectroscopy. The Mossbauer spectra parameters evidenced
two phases. The first phase is a magnetic ordering one corresponding to iron oxides. The second
phase is a paramagnetic one and represents the iron in granat structure.
The ratio between the ferric and ferrous ionic occupancies in the granat structure is discussed and
compared with the data of the chemical analysis on the investigated samples.
The new data are obtained about the relative ratio between the end-members of the serie
spessartine-calderite. The pressure and temperature genesis conditions of the natural deposits
from which the sample have been extracted are correlated with Mossbauer spectrum parameters.
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