Crystal growth of diamond from a phosphorus solvent under high pressure–high temperature conditions

Abstract

Abstract Crystal growth of diamond in a phosphorus solvent was studied on a seed of natural octahedral diamond at high pressures and high temperatures of 6.2–6.5 GPa and 1600–1700°C for 5–23 h. Although new growth layers of diamond up to 30 μm in thickness were observed on {111} faces of a seed, growth almost stopped within the first 5 h caused by the following occurrence of spontaneous nucleation. The growth layer was usually gray or bluish gray in color and the surface became undulated with dense triangular growth hillocks and growth steps of 〈110〉 directions. On the grown surface were observed two other characteristic features: one is a circular depression with various size particularly observed in the beginning of the growth and the other is a peculiar growth step with the direction indexed as 〈321〉.