Fig. 1. FESEM photographs of HPHT synthetic polycrystalline
diamond from Fe-C(H) system.

YANG Zhi-jun1，2, LIANG Rong1, PENG Ming-sheng1, FAN Hua-qi1, LIU Xiao-yu1, PENG Zhuo-lun1

(1.Department of Earth Sciences, Sun Yat-sen University, Guangzhou 510275, China；
2.Guangdong Provincial Key Laboratory of Mineral Resource Exploration & Geological Processes, Guangzhou 510275, China )

Abstract：The HPHT synthetic polycrystalline diamonds form Fe-C(H) system have an unevenly clustered distribution on the disk. Diamond grains randomly oriented in Polycrystalline have octahedral habit and different sizes. Also, there are Zigzag stripes on the gain surfaces and widespread development of plastic deformation and other defects in the diamond grains. The diamond grain boundaries are clear and solid contact mutant. Based on the crystal nucleation and crystal growth theory, only parts of experimental results of the polycrystalline can be explained. The usage of carbon atom coordination tetrahedron growth units model in explaining the formation mechanism of the polycrystalline entails further studying. The In-depth analysis of the formation mechanism of the high pressure-high temperature synthetic polycrystalline diamond from Fe-C(H) system will not only optimize diamond synthesis craft and improve the grade of the polycrystalline diamond, but also provide scientific clues for the formation mechanisms of natural polycrystalline diamond.

Key words：polycrystalline diamond; formation mechanism; Fe-C(H) system; high pressure-high temperature

Corresponding author: YANG Zhi-jun,  E-mail: yangzhj@mail.sysu.edu.cn

ACTA MINERALOGICA SINICA Vol. 30, No. 3, 2010, Page 405-410