TY - JOUR

T1 - The characteristic photoluminescence and EPR features of superdeep diamonds (São-Luis, Brazil)

AU - Yuryeva, Olga P.

AU - Rakhmanova, Mariana I.

AU - Nadolinny, Vladimir A.

AU - Zedgenizov, Dmitry A.

AU - Shatsky, Vladislav S.

AU - Kagi, Hiroyuki

AU - Komarovskikh, Andrey Yu

PY - 2015/10/1

Y1 - 2015/10/1

N2 - Photoluminescence (PL) spectroscopy and electron paramagnetic resonance (EPR) were used for the first time to characterize properties of superdeep diamonds from the São-Luis alluvial deposits (Brazil). The infrared measurements showed the low nitrogen content (>50 of 87 diamonds from this locality were nitrogen free and belonged to type IIa) and simultaneously the extremely high level of nitrogen aggregation (pure type IaB being predominant), which indicates that diamonds under study might have formed under high pressure and temperature conditions. In most cases, PL features excited at various wavelengths (313, 473, and 532 nm) were indicative of different growth and post-growth processes during which PL centers could be formed via interaction between vacancies and nitrogen atoms. The overall presence of the 490.7 nm, H3, and H4 centers in the luminescence spectra attests to strong plastic deformations in these diamonds. The neutral vacancy known as the GR1 center has probably occurred in a number of crystals due to radiation damage in the post-growth period. The 558.5 nm PL center is found to be one of the most common defects in type IIa samples which is accompanied by the EPR center with g-factor of 2.00285. The 536 and 576 nm vibronic systems totally dominated the PL spectra of superdeep diamonds, while none of “normal” diamonds from the Mir pipe (Yakutia) with similar nitrogen characteristics showed the latter three PL centers.

AB - Photoluminescence (PL) spectroscopy and electron paramagnetic resonance (EPR) were used for the first time to characterize properties of superdeep diamonds from the São-Luis alluvial deposits (Brazil). The infrared measurements showed the low nitrogen content (>50 of 87 diamonds from this locality were nitrogen free and belonged to type IIa) and simultaneously the extremely high level of nitrogen aggregation (pure type IaB being predominant), which indicates that diamonds under study might have formed under high pressure and temperature conditions. In most cases, PL features excited at various wavelengths (313, 473, and 532 nm) were indicative of different growth and post-growth processes during which PL centers could be formed via interaction between vacancies and nitrogen atoms. The overall presence of the 490.7 nm, H3, and H4 centers in the luminescence spectra attests to strong plastic deformations in these diamonds. The neutral vacancy known as the GR1 center has probably occurred in a number of crystals due to radiation damage in the post-growth period. The 558.5 nm PL center is found to be one of the most common defects in type IIa samples which is accompanied by the EPR center with g-factor of 2.00285. The 536 and 576 nm vibronic systems totally dominated the PL spectra of superdeep diamonds, while none of “normal” diamonds from the Mir pipe (Yakutia) with similar nitrogen characteristics showed the latter three PL centers.

KW - Annealing

KW - Electron irradiation

KW - EPR

KW - Photoluminescence (PL) spectroscopy

KW - Superdeep diamond

UR - http://www.scopus.com/inward/record.url?scp=84943352936&partnerID=8YFLogxK

U2 - 10.1007/s00269-015-0756-7

DO - 10.1007/s00269-015-0756-7

M3 - Article

AN - SCOPUS:84943352936

VL - 42

SP - 707

EP - 722

JO - Physics and Chemistry of Minerals

JF - Physics and Chemistry of Minerals

SN - 0342-1791

IS - 9

ER -