Photoluminescence of silicon-vacancy defects in nanodiamonds of different chondrites

摘要: Photoluminescence spectra show that silicon impurity is present in lattice of some nanodiamond grains (ND) various chondrites as a silicon-vacancy (SiV) defect. The relative intensity the SiV band diamond-rich separates depends on chemical composition meteorites and size ND grains. strongest signal found for enriched small grains; thus confirming our earlier conclusion defects preferentially reside smallest (less than 2 nm) difference intensities luminescence individual are due to variable conditions thermal metamorphism their parent bodies and/or uneven sampling nanodiamonds populations. Annealing air eliminates surface sp2-carbon, consequently, enhanced. Strong well-defined absorption defect promising feature locate cold (< 250 {\deg}C) space.