Optical absorption and EPR studies on tenorite mineral

Area of Science:

• Mineralogy
• Solid-state Chemistry
• Spectroscopy

Background:

• Tenorite (CuO) is a significant copper-containing mineral.
• Understanding its electronic structure is key to mineral characterization.
• Previous studies provide context for copper ion behavior in mineral matrices.

Purpose of the Study:

• To characterize the mineral tenorite (CuO) using optical absorption and EPR spectroscopy.
• To elucidate the electronic structure and coordination of Cu(II) ions within the mineral.
• To compare spectral parameters with other copper-bearing minerals.

Main Methods:

• Electron Paramagnetic Resonance (EPR) spectroscopy at room and liquid nitrogen temperatures.
• Optical absorption spectroscopy.
• Analysis of spin Hamiltonian parameters (g and D).

Main Results:

• EPR studies indicated two closely interacting Cu(II) ions, suggesting a d(2) type structure.
• Calculated spin Hamiltonian parameters: g=2.160 and D=125 G.
• Optical absorption revealed Cu(II) in two distinct tetragonal C(4v) symmetries and octahedral coordination, with three energy sets.

Conclusions:

• The spectral data confirm the presence of Cu(II) in tenorite with specific coordination environments.
• The interacting Cu(II) ions and determined symmetries provide insights into the mineral's electronic properties.
• Comparison with other copper minerals aids in understanding variations in crystal field effects.