Cathodoluminescence characterization of enstatite

Enstatite in meteorite shows various emissions of cathodoluminescence (CL), and CL emission in terrestrial enstatite has been confirmed in this study. The CL spectra of these enstatite exhibit two broad emission bands at around 400 nm in a blue region and at around 670 nm in a red region. The emission components obtained by a spectral deconvolution can be assigned to impurity centers of Cr3+ (1.70–1.75 eV) and Mn2+ (1.85–1.90 eV) and to three defect centers (2.72–2.75, 3.18, and 3.87 eV). The emission component at 3.18 eV might be associated to the defect center derived from structural distortion by the substitution of Al for Si in a tetrahedral site. Extraterrestrial enstatite gives a characteristic emission at 3.87 eV in a blue to UV region, which is not detected in the terrestrial enstatite, suggesting radiation–induced defect by cosmic rays.