Transformation of diamond to graphite under heat treatment at low pressure

Autor:	Alexey A. Gippius, R. A. Khmelnitsky
Rok vydání:	2013
Předmět:	Materials science Material properties of diamond Nucleation Mineralogy chemistry.chemical_element Diamond engineering.material Oxygen chemistry Metastability engineering General Materials Science Graphite Surface layer Composite material Instrumentation Carbon
Zdroj:	Phase Transitions. 87:175-192
ISSN:	1029-0338 0141-1594
DOI:	10.1080/01411594.2013.807429
Popis:	Diamond is a very persistent metastable form of carbon. At low pressure, graphitization of the diamond surface is observed at temperatures lower than 1700 °C. The basic cause of this is known to be interaction with oxygen. In the present paper, the microphysics of the phenomenon of diamond surface graphitization was studied. It has been shown that surface graphitization proceeds in several stages. First, a thin surface layer of graphite is developed due to interaction with oxygen (and probably other substances). As temperature is increased, nuclei of 5–10 nm in size are formed within it. The graphite nuclei are capable of migrating along the surface of diamond. They form ‘nests,’ where they are coalesced into aggregates 10–100 nm in size. These ‘nests’ give rise to diamond surface layer graphitization, which proceeds along diamond {211} crystallographic planes and forms graphitization figures. At this stage, the factor that determines the transformation is the pressure exerted on graphitizing material by ...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::9a46c365d18f7fdaab41590d0859a249 https://doi.org/10.1080/01411594.2013.807429 Zobrazit plný text záznamu