日時 ： ２００９年１２月１１日（金）※16：30～
場所 ： 愛媛大学総合研究棟Ⅰ 4F 共通会議室（理学部構内）
要 旨
Cubic carbon nitride (C-C3N4) is expected to have potentially an extremely high bulk modulus (K0=496 GPa) equivalent to or even exceeding that of diamond, according to several theoretical studies (e.g. Teter and Hemley, 1996). Teter and Hemley’s calculation showed that it can experimentally be synthesized from graphitic C3N4 at about 12 GPa and quenchable to the ambient condition. Since then, although many scientists have tried to synthesize the dense super-hard phase of C3N4, no evidence for successful synthesis has been shown. A recent study by Ming et al. (2006) reported that a metastable cubic C3N4 is obtained upon decompression of a new high pressure form of C3N4, which is synthesized from graphitic-C3N4 at 23 GPa, 1600 K in a laser-heated diamond anvil cell (LHDAC). The metastable cubic phase was found to have a P-type unit cell with a lattice parameter of a=3.878 A. This is not correspondent to any C3N4 structures so far theoretically calculated.
問い合わせ先：土屋 卓久 TEL （089）927-8198
E-mail takut@sci.ehime-u.ac.jp
