Swift heavy ion irradiation of muscovite and biotite substrates

We report magnetic and spectroscopic studies of naturally occurring layered phyllosilicates; muscovite and biotite of Sikkim Himalaya. The minerals are characterised by SEM–EDS, powder X-ray diffraction (pXRD), electron paramagnetic resonance (EPR) and magnetometry. EPR spectra of muscovite and its axial dependence show the presence of Mn2+ ions in the silicate sheets. The samples are irradiated with 120 MeV Au ions and the consequent structural modifications are analysed. The irradiation does not influence the compositions, structural and magnetic properties of these micas. Therefore, both muscovite and biotite are more suitable for use as substrates than many other materials routinely used as substrates for swift heavy ion irradiation measurements.