Raman spectroscopic investigation of heavy ion damage induced by focused ion beam in lunar breccias 15405, 15445 and reference minerals — E8 Intelligence Research

This study investigates the response of lunar breccia minerals and selected reference materials to accelerated Ga+ ion irradiation using focused ion beam (FIB) processing combined with Raman spectroscopy. Anorthite and pyroxene bearing clasts from Apollo 15 breccias 15405 and 15445 were examined alongside monocrystalline silicon, magnetite, and pyrite to evaluate mineral specific structural modifications induced by heavy ion exposure. Samples were characterized by Raman spectroscopy before and after irradiation with 30 keV Ga+ ions at four beam currents (0.43, 0.79, 2.5, and 9.3 nA). Silicate phases exhibited band broadening, peak shifts, and partial amorphization consistent with increasing lattice disorder. Monocrystalline silicon showed progressive damage of the crystalline structure, while magnetite and pyrite displayed enhanced structural disorder and modifications of Fe-bearing spectral features. At the highest irradiation conditions, Ga implantation and loca Author: Andrew Stewart Caldin, Independent Researcher, UK. Part of the E8 Intelligence Research series. Platform: e8intelligence.com