EPR and optical absorption characteristics of sodic plagioclase from granite pegmatite in Kadavur,India |
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Authors: | S. Vijay Anand M. S. Pandian S. Mithira R. V.S.S.N. Ravikumar |
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Affiliation: | 1. Department of Earth Sciences , Pondicherry University , Puducherry, India;2. Department of Chemistry , Pondicherry University , Puducherry, India;3. Department of Chemistry , Pondicherry University , Puducherry, India;4. Department of Physics , Acharya Nagarjuna University , Nagarjuna Nagar, India |
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Abstract: | The electron paramagnetic resonance (EPR) spectra of sodic plagioclase from dykes of granitic pegmatite occurring in the Kadavur area, Tamil Nadu, India, were examined at room temperature to identify paramagnetic impurities in a “low plagioclase” using EPR and optical techniques. The EPR spectra showed the presence of Fe(III) and Mn(II) impurities. After heating the plagioclase samples for various durations at 600 °C, it has been observed that the concentration of Mn(II) remained as such in one sample but completely disappeared in another sample, while there was no change in Fe(III) ion concentration after the heat treatment in either sample. Optical absorption spectra also showed Fe(II) and Fe(III) in addition to Ti(III) impurities in sodic plagioclase before heating, while after heating the relative concentration of Fe(II) and Fe(III) changed, accompanied by the disappearance of Ti(III). |
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Keywords: | EPR optical spectroscopy sodic plagioclase granite pegmatite impurities annealing |
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