Atom force microscopy study on HTHP as-grown diamond single crystals

Citation
Lw. Yin et al., Atom force microscopy study on HTHP as-grown diamond single crystals, APPL PHYS A, 73(5), 2001, pp. 653-657
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
ISSN journal
0947-8396 → ACNP
Volume
73
Issue
5
Year of publication
2001
Pages
653 - 657
Database
ISI
SICI code
0947-8396(200111)73:5<653:AFMSOH>2.0.ZU;2-P
Abstract
For understanding the mechanism of diamond growth at high temperature-high pressure (HTHP) from a metallic catalyst-graphite system, it is of great in terest to perform atomic force microscopy (AFM) experiments. which provide a unique technique different from that of normal optical and electronic mic roscopy studies, to study the topography of HTHP as-grown diamond single cr ystals. In the present paper, we report first AFM results on diamond single crystals grown from a Fe-Ni-C system at HTHP to reveal the growth mechanis m of diamond single crystals at HTHP AFM images for as-grown diamond sample s show dark etch pits on the (111) surface, indicating dislocations. Some f ine particles about 100-300 nm in dimension were directly observed on the ( 100) diamond surface. These particles are believed to have been formed thro ugh transition of graphite to diamond under the effect of the catalyst and to have been transported to the growing diamond surface through a metallic thin film by diffusion. The roughness of the (100) diamond surface is found to be about several tens of nanometers through profile analysis. The diamo nd growth at HTHP, in a sense, could be considered as a process of unificat ion of these fine diamond particles or of carbon-atom-cluster recombination on the growing diamond crystal surface. Successive growth interlayer steps on the (111) diamond surface were systemically examined, The heights of th e growth interlayer steps were measured by sectional analysis. It was shown that the heights of the growth interlayer steps are quite different and ra nge from about 10 to 25 nm. The source of the interlayer steps might be dis locations. The diamond-growth mechanism at HTHP could be indicated by the A FM topography of the fine diamond particles and the train-growth interlayer steps on the as-grown diamond surfaces.