Сообщение
vano » Пт ноя 16, 2007 7:40 pm
А такое не пойдет?
Phase relationships in the Si3N4-SiO2-Lu2O3 system. Hirosaki, Naoto; Yamamoto, Yoshinobu; Nishimura, Toshiyuki; Mitomo, Mamoru; Takahashi, Junichi; Yamane, Hisanori; Shimada, Masahiko. National Institute for Materials Science, Ibaraki, Japan. Journal of the American Ceramic Society (2002), 85(11), 2861-2863. Publisher: American Ceramic Society, CODEN: JACTAW ISSN: 0002-7820. Journal written in English. CAN 138:307851 AN 2002:876298 CAPLUS
Abstract
Phase relationships in the Si3N4-SiO2-Lu2O3 system were investigated at 1850° in 1 MPa N2. Only J-phase, Lu4Si2O7N2 (monoclinic, space group P21/c, a = 0.74235(8) nm, b = 1.02649(10) nm, c = 1.06595(12) nm, and b = 109.793(6)°) exists as a lutetium silicon oxynitride phase in the Si3N4-SiO2-Lu2O3 system. The Si3N4/Lu2O3 ratio of 1, corresponding to the M-phase compn., results in a mixt. of Lu-J-phase, b-Si3N4, and a new phase of Lu3Si5ON9, having orthorhombic symmetry, space group Pbcm (No. 57), with a = 0.49361(5) nm, b = 1.60622(16) nm, and c = 1.05143(11) nm. The new phase is best represented in the new Si3N4-LuN-Lu2O3 system. The phase diagram suggests that Lu4Si2O7N2 is an excellent grain-boundary phase of silicon nitride ceramics for high-temp. applications.