Combined Cathodoluminescence and Micro-Raman Study of Helium-Ion-Implanted Albite

Abstract

ABSTRACT Cathodoluminescence (CL) spectra of experimentally radiated albite at 4.0 MeV energy of He+ ion implantation have red emissions at 700−750 nm, of which the intensities increase with an increase in the radiation dose. These emissions are assigned to a radiation-induced defect center. Pseudocolor CL images of the implanted samples show red CL halo on the implanted surface, of which thickness is approximately 14 µm corresponding to a theoretical range of He+ ion implantation of 4.0 MeV. 2D Raman mapping of the peak at 508 cm−1 for CL halo area indicates minimum intensity and maximum full width at half maximum at ∼14 µm from the implanted surface, suggesting production of radiation-induced defect center due to a partial breaking of the framework structure. CL spectral deconvolution of the red emission reveals a Gaussian component at 1.861 eV attributed to the defect center. The integral intensity of this component closely correlates with the radiation dose as a function of radiation-induced defect center, but does not depend on the density and distribution of other emission centers related to CL of albite, the presence of microstructures or texture, and crystallographic orientation. CL spectral deconvolution is expected to be used for quantitative estimation of alpha radiation dose from natural radionuclides on Na-rich feldspar as an indicator for geodosimetry.