TY - JOUR

T1 - Manifestation of diamond sectoriality during dissolution and graphitization

AU - Khokhryakov, Alexander F.

AU - Palyanov, Yuri N.

PY - 2018/11/15

Y1 - 2018/11/15

N2 - We studied the morphology of dissolution and graphitization forms of sectorial natural and synthetic diamonds. Experiments on diamond dissolution (graphitization) were performed in model systems of different composition in a wide range of temperatures and pressures. It was found that, after dissolution, the raised (positive) and etched (negative) regions of the relief are formed along the outcrops of the growth sectors on the round surface of the diamond crystals. The relief patterns associated with the sectorial structure of crystals do not affect in the geometry of dissolution forms, which is mainly determined by external factors such as solvent composition, redox conditions, and process temperature. Based on the relative height of the relief elements at the outcrops of different growth sectors, it is concluded that the rate of dissolution of the growth sectors of synthetic diamonds decreases in the sequence {1 0 0}, {1 1 1}, {3 1 1}, {1 1 0}. In graphitization, the highest graphitization rate is observed in the growth sectors of {1 0 0} faces as well. As a result, deep grooves are formed on the growth sectors {1 0 0} faces. We assume that the dissolution features of various growth sectors are determined by the dependence of the rate of diamond dissolution (graphitization) on the concentration of nitrogen impurities in the growth sectors of various simple forms.

AB - We studied the morphology of dissolution and graphitization forms of sectorial natural and synthetic diamonds. Experiments on diamond dissolution (graphitization) were performed in model systems of different composition in a wide range of temperatures and pressures. It was found that, after dissolution, the raised (positive) and etched (negative) regions of the relief are formed along the outcrops of the growth sectors on the round surface of the diamond crystals. The relief patterns associated with the sectorial structure of crystals do not affect in the geometry of dissolution forms, which is mainly determined by external factors such as solvent composition, redox conditions, and process temperature. Based on the relative height of the relief elements at the outcrops of different growth sectors, it is concluded that the rate of dissolution of the growth sectors of synthetic diamonds decreases in the sequence {1 0 0}, {1 1 1}, {3 1 1}, {1 1 0}. In graphitization, the highest graphitization rate is observed in the growth sectors of {1 0 0} faces as well. As a result, deep grooves are formed on the growth sectors {1 0 0} faces. We assume that the dissolution features of various growth sectors are determined by the dependence of the rate of diamond dissolution (graphitization) on the concentration of nitrogen impurities in the growth sectors of various simple forms.

KW - A1. Defects

KW - A1. Dissolution

KW - A1. Graphitization

KW - A1.Crystal morphology

KW - B1.Diamond

UR - http://www.scopus.com/inward/record.url?scp=85053018562&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2018.09.008

DO - 10.1016/j.jcrysgro.2018.09.008

M3 - Article

AN - SCOPUS:85053018562

VL - 502

SP - 1

EP - 6

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

ER -