Characterization of a growth-front interface in a HPHT-grown diamond crystal by transmission electron microscopy

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2001-03, Vol.72 (3), p.373-375
• Main Authors: YIN, L. W, LI, M. S, ZOU, Z. D, SUN, D. S, HAO, Z. Y, GONG, Z. G, YAO, Z. Y
• Format: Article
• Language: English
• Subjects: Clusters; Cross-disciplinary physics: materials science; rheology; Crystals; Diamonds; Electron microscopy; Exact sciences and technology; Graphite; Growth from solutions; Joints; Materials science; Methods of crystal growth; physics of crystal growth; Physics; Supercooling; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Transformations
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s003390100743

The growth-front interface of a diamond single crystal, which was grown from the Fe-Ni-C system under high pressure and high temperature (HPHT), has been directly observed by transmission electron microscopy (TEM) for the first time. The presence of a cellular interface suggests that the diamond is grown from solution and there exists a narrow supercooling zone in front of the solid--liquid interface. Diamond-growth parallel layers were also found, which indicates that the diamond grows from solution layer by layer. It provides direct evidence that the diamond is synthesized through graphite dissolution and transformation to subcritical diamond particles in a molten catalyst, diamond subcritical particle connection to form diamond clusters, diffusion of the diamond clusters to the growing diamond, and unification of the diamond clusters on the growing diamond crystal.