TY - JOUR

T1 - Effect of sulfur on diamond growth and morphology in metal-carbon systems

AU - Palyanov, Yuri N.

AU - Borzdov, Yuri M.

AU - Khokhryakov, Alexander F.

AU - Bataleva, Yuliya V.

AU - Kupriyanov, Igor N.

PY - 2020/9/7

Y1 - 2020/9/7

N2 - In this paper, we report on the effect of sulfur additives (as FeS2 in the Fe90Ni10-C system) on the growth processes, morphology, and defect-and-impurity content of diamond crystals at 6 GPa and 1400 °C. It has been established that the sulfide component plays an inhibitory role in diamond crystallization processes. As the concentration of the sulfur additive (XS) in the system increases from 0 to 20 wt%, the degree of graphite-to-diamond transformation decreases from 100% to zero and the solubility of carbon in the melt decreases from 6.6 to 0.4 wt%. Addition of sulfur to the growth system leads to the appearance of metastable graphite and its amount increases with increasing sulfur content. It is found that the concentration of nitrogen impurities in the synthesized diamonds decreases from 50-100 ppm at XS = 0 to 5-10 ppm at XS = 10-15 wt%. Sulfide additives lead to the transformation of flat-faced octahedral diamond crystals to specific crystals with the elements of antiskeletal growth and fragmentation of their vertices. It is suggested that the main reason for the change in the morphology of diamond crystals is the selective adsorption of sulfide clusters on planar defects located mainly near the vertices of the octahedron. Inhibition of the propagation of growth layers on the {111} faces of diamond crystals leads to the formation of faceted macrosteps, the fragmentation of the crystal vertices and the polycentric structure of the faces. This journal is

AB - In this paper, we report on the effect of sulfur additives (as FeS2 in the Fe90Ni10-C system) on the growth processes, morphology, and defect-and-impurity content of diamond crystals at 6 GPa and 1400 °C. It has been established that the sulfide component plays an inhibitory role in diamond crystallization processes. As the concentration of the sulfur additive (XS) in the system increases from 0 to 20 wt%, the degree of graphite-to-diamond transformation decreases from 100% to zero and the solubility of carbon in the melt decreases from 6.6 to 0.4 wt%. Addition of sulfur to the growth system leads to the appearance of metastable graphite and its amount increases with increasing sulfur content. It is found that the concentration of nitrogen impurities in the synthesized diamonds decreases from 50-100 ppm at XS = 0 to 5-10 ppm at XS = 10-15 wt%. Sulfide additives lead to the transformation of flat-faced octahedral diamond crystals to specific crystals with the elements of antiskeletal growth and fragmentation of their vertices. It is suggested that the main reason for the change in the morphology of diamond crystals is the selective adsorption of sulfide clusters on planar defects located mainly near the vertices of the octahedron. Inhibition of the propagation of growth layers on the {111} faces of diamond crystals leads to the formation of faceted macrosteps, the fragmentation of the crystal vertices and the polycentric structure of the faces. This journal is

KW - HIGH-PRESSURE

KW - IB DIAMOND

KW - CRYSTAL-GROWTH

KW - S-C

KW - CRYSTALLIZATION

KW - IRON

KW - LIQUID

KW - GRAPHITE

KW - NITROGEN

KW - IMPURITY

UR - http://www.scopus.com/inward/record.url?scp=85090011363&partnerID=8YFLogxK

U2 - 10.1039/d0ce00865f

DO - 10.1039/d0ce00865f

M3 - Article

AN - SCOPUS:85090011363

VL - 22

SP - 5497

EP - 5508

JO - CrystEngComm

JF - CrystEngComm

SN - 1466-8033

IS - 33

ER -