METHOD OF GROWING DIAMOND FROM GRAPHITE Russian patent published in 1997 - IPC

FIELD: production of artificial diamonds. SUBSTANCE: method is effected in a high- pressure chamber using pulse-periodical laser irradiation of diamond- graphite interface through one of the chamber walls transparent for laser radiation. In this chamber being of the diamond anvil type, pressure in the range from about 5 to some 50 GPa (depending on chamber potentialities) is maintained, whereas laser emission pulse heats very narrow skin-layer of graphite to temperatures of order of 1000 K, which are sufficient to convert graphite into diamond. Because of large temperature gradients in skin-layer and high heat conductance of diamond, anomalously rapid cooling of layer and its transformation into laser-transparent diamond occur. Wavelength of laser emission should fall into diamond transparency range from about 0.2 to about 5 mcm. Next laser pulse should heat next graphite layer and convert it into diamond, that is, as if laser emission would stimulate intergrowth of transparent diamond inside non-transparent graphite. EFFECT: improved procedure. 1 dwg