TITLE DIAMOND WITH Y-DEFECTS: SPECTROSCOPY AND TRANSMISSION ELECTRON MICROSCOPY
A.A. Shiryaev1, E.F. Vasilev2, A.L. Vasil’ev3,4, V.V. Artemov3, N.V. Gubanov5, D.A. Zedgenizov5
1Frumkin Institute of physical chemistry and electrochemistry RAS, Moscow, Russia
2Saint Petersburg mining university, Saint Petersburg, Russia
3 Shubnikov Institute of Crystallography, Kurchatov Complex of Crystallography and Photonics, National Research Centre "Kurchatov Institute," Moscow, Russia
4Moscow Institute of Physics and Technology, Dolgoprudny, Russia
5Zavaritsky Institute of Geology and Geochemistry UB RAS, Ekaterinburg, Russia
Keywords: diamond, Y-defect, spectroscopy, transmission electron microscopy
Abstract
The paper presents results of investigation of a natural Ib-IaA diamond containing Y-defects from Yubileinaya kimberlite pipe. Analysis of spatial distribution of A and C defects and intensity of IR absorption at Raman frequency (1332 сm-1) reveals anticorrelation between these defects. Transmission electron microscopy of a zone with abundant Y-defects shows presence of dislocations in various configurations and numerous clusters of point defects generated by non-conservative dislocation movement. Extended defects with shape resembling thin (1-3 nm) rhombic plates with the largest dimension up to 5-20 nm. Analysis of contrast of these defects shows that they represent nanosised voids (vacancy clusters). It is suggested that the defects were formed by annihilation of dislocation dipoles with subsequent growth by consumption of vacancies produced by non-conservative motion of dislocations. Upon excitation by 787 nm laser, in region 800-900 nm of photoluminescence spectra numerous narrow lines are observed, their intensity and position show irregular temporal variations. Such behavior (blinking) was earlier note for hydrogenated nanodiamonds. It is suggested that unusual behavior of the luminescence lines may be explained by recombination processes on internal walls of the voids.
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