In situ X-ray observations of the decomposition of brucite and the graphite-diamond conversion in aqueous fluid at high pressure and temperature

Autor:	Masaaki Yamakata, Taku Okada, Wataru Utsumi, H. Kaneko, Osamu Shimomura
Rok vydání:	2002
Předmět:	Aqueous solution Brucite Chemistry X-ray Analytical chemistry Mineralogy Diamond engineering.material Catalysis Geochemistry and Petrology engineering General Materials Science Graphite Solubility Periclase
Zdroj:	Physics and Chemistry of Minerals. 29:439-445
ISSN:	1432-2021 0342-1791
Popis:	An experimental technique to make real-time observations at high pressure and temperature of the diamond-forming process in candidate material of mantle fluids as a catalyst has been established for the first time. In situ X-ray diffraction experiments using synchrotron radiation have been performed upon a mixture of brucite [Mg(OH)2] and graphite as starting material. Brucite decomposes into periclase (MgO) and H2O at 3.6 GPa and 1050 °C while no periclase is formed after the decomposition of brucite at 6.2 GPa and 1150 °C, indicating that the solubility of the MgO component in H2O greatly increases with increasing pressure. The conversion of graphite to diamond in aqueous fluid has been observed at 7.7 GPa and 1835 °C. Time-dependent X-ray diffraction profiles for this transformation have been successfully obtained.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::4091562082ac05ec8759c791aadfcc61 https://doi.org/10.1007/s00269-002-0254-6 Zobrazit plný text záznamu Full text from SpringerLink