Paramagnetic Resonance Absorption Spectra of Divalent Manganese and Trivalent Iron in Calcite

摘要

The electron paramagnetic resonance absorption spectra of divalent manganese and trivalent iron in single crystals of natural calcite were observed at x-band frequencies. Careful relative intensity measurements of the doublet structure of these spectra, resulting from the difference in the crystal-line electric fields at the two calcium Ca(++) substitutional sites occupied by manganese Mn(++) and iron Fe(+++) ions, were made. These measurements showed that manganese does not preferentially occupy either of the two magnetically nonequivalent sites, while iron shows preferential occupation of one site. In both cases, samples of approximately the same ion concentration were used.