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Electron paramagnetic resonance and optical absorption spectral studies on chalcocite
S Lakshmi Reddy1, Md Fayazuddin, Ray L Frost
1Department of Physics, SVD College, Kadapa, India. slreddy_in@yahoo.com
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
|February 28, 2007
Summary
This study used electron paramagnetic resonance (EPR) and optical absorption spectroscopy to analyze a chalcocite mineral sample. The analysis confirmed the presence of Mn(II), Fe(III), and Cu(II) impurities within the mineral structure.
Area of Science:
- Mineralogy
- Solid-state chemistry
- Spectroscopy
Background:
- Chalcocite (Cu2S) is a significant copper ore mineral.
- Understanding impurity incorporation is crucial for mineral processing and characterization.
- Spectroscopic techniques offer insights into the local environment of ions within mineral lattices.
Purpose of the Study:
- To characterize the impurity ions present in a Shaha, Congo chalcocite sample.
- To determine the structural environment of identified impurity ions using spectroscopic methods.
Main Methods:
- Electron Paramagnetic Resonance (EPR) spectroscopy was employed to identify paramagnetic species.
- Optical Absorption (OA) spectroscopy was used to probe the electronic transitions of transition metal ions.
- Mid-Infrared (Mid-IR) spectroscopy was utilized to identify fundamental vibrations.
Main Results:
- EPR confirmed the presence of manganese (Mn(II)), iron (Fe(III)), and copper (Cu(II)) ions.
- Optical absorption data indicated Fe(III) occupies an octahedral site.
- Cu(II) was found in a rhombically distorted octahedral environment, and Mid-IR spectra revealed contributions from water and sulfate.
Conclusions:
- The study successfully identified and characterized multiple impurity ions in chalcocite.
- Spectroscopic data provided detailed information on the coordination environment of Fe(III) and Cu(II) impurities.
- The presence of water and sulfates suggests potential alteration or secondary mineralization processes.
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