Ultradisperse-Diamond Nanoclusters. Fractal Structure and Diamond–Graphite Phase Transition

✍ Scribed by M.V Baidakova; V.I Siklitsky; A.Ya Vul

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 242 KB
• Volume: 10
• Category: Article
• ISSN: 0960-0779
• DOI: 10.1016/s0960-0779(98)00247-1

✦ Synopsis

A systematic study of the diamondÐgraphite structural phase transition in ultradisperse!dia! mond clusters obtained by the detonation technique is reported[ Samples of two types\ di}ering in the kinetics of detonation!product cooling\ were investigated[ The phase transition was achieved under heating in an inert atmosphere in the temperature range 619Ð0399 K[ X!ray characterization showed the ultra! disperse!diamond\ irrespective of the cooling rate used\ to be a cluster material possessing a diamond structure with a characteristic nanocrystal size of 33 A Ä [ The diamondÐgraphite structural phase transition in ultradisperse diamond is shown to start from the cluster surface inwards at T pt ¼0199 K\ i[e[\ at substantially lower temperatures than is the case with bulk diamond single crystals[ Ultradisperse!diamond clusters are shown to be fractal objects and the character of variation of the fractal dimension in the course of the diamondÐgraphite phase transition is studied[ Þ 0888 Elsevier Science Ltd[ All rights reserved