High-pressure, high-temperature processing of low-nitrogen boron-doped diamond

HPHT-Treated Diamonds

“…If the pressure applied during HPHT treatment is not sufficient for the stabilization of the diamond lattice, the complete graphitization of diamond at a temperature of 2,300°C may occur in a matter of a minute (Chepurov et al 2008). If the pressure applied during HPHT treatment is not sufficient for the stabilization of the diamond lattice, the complete graphitization of diamond at a temperature of 2,300°C may occur in a matter of a minute (Chepurov et al 2008).…”

Core growth of detonation nanodiamonds under high-pressure annealing

“…47 Concerning the broad band near 1000 cm À1 , there are some other alternative explanations for this, such as the surface plasmon modes 47 or trans-polyacetylene (t-PA) structures on the particle surface. 48 The growth of the nanocrystals of detonation diamond during HPHT sintering evidently occurred due to the phase transition of carbon from a non-diamond phase (sp 2 ) into the sp 3 -state. Comparing the dependence of the integral intensity of D-and G-spectral bands on the sintering temperature (Fig.…”

“…1 Different approaches have been used to affect the core-shell microstructure, and the one we used is by annealing at high pressure and high temperature (HPHT), which changes the properties of both natural and synthetic diamonds. 2,3 The growth of detonation diamond nanocrystals under HPHT is obviously related to the phase transformation of graphite into diamond. The transition of carbon atoms from the sp 2 to sp 3 state during the annealing of detonation diamonds in a hydrogen atmosphere is well known, with the graphite-to-diamond transition resulting in nanocrystals growth up to the micron size.…”

“…2,3 The growth of detonation diamond nanocrystals under HPHT is obviously related to the phase transformation of graphite into diamond. The transition of carbon atoms from the sp 2 to sp 3 state during the annealing of detonation diamonds in a hydrogen atmosphere is well known, with the graphite-to-diamond transition resulting in nanocrystals growth up to the micron size. 4 The growth of detonation diamond crystals aer a high-pressure and high-temperature process has an impact on the Raman scattering spectra.…”

Defect-impurity composition of diamond crystals grown in magnesium-carbon system

“…3). Концентрация нескомпенсированного бора в кристалле рассчитана с помощью соотношения [16]: Кроме того, в выращенных кристаллах, в которых не наблюдается деформация кристаллической решет-ки, и проявляются собственные решеточные колебания, присутствует полоса поглощения при 2810 см -1 , соответствующая примеси бора, а также полосы в области многофононного поглощения при 3726 см -1 и 4098 см -1 (рис. 3).…”