抄録
Silicon nitride-based ceramics having high functional mechanical properties are described with respect to phase relationships between Si3N4 and the grain boundary phases of rare-earth silicon-oxynitrides. The crystal structures of La4Si2O7N2 (La-J-phase) and Lu4Si2O7N2 (Lu-J-phase) have been determined by time-of-flight neutron powder diffractometry. The local structures of Si2 (O, N) 7 ditetrahedra including O and N atom distribution in the rare-earth silicon-oxynitrides are revealed.
