Electron paramagnetic resonance and optical absorption spectra of fresh water mussel Lamellidens marginalis shells

Abstract

Electron Paramagnetic Resonance (EPR) and optical absorption spectra of fresh water mussel Lamellidens marginalis shells have been studied at room temperature (300 K). The EPR spectra exhibit a group of five fine structure transitions, characteristic of the Mn 2+ion. From the observed spectra the spin-Hamiltonian and zero-field splitting parameters have been determined. The observed spin-Hamiltonian parameters are found to be very near to the parameters reported for aragonite like shells. The optical absorption spectrum exhibits bands characteristic of Mn 2+ ions in octahedral symmetry. From the observed spectrum, the crystal field parameters were then evaluated.