Phase Relationships in the Si3N4–SiO2–Lu2O3 System
Phase Relationships in the Si3N4–SiO2–Lu2O3 System
复制标题
Si3N4–SiO2–Lu2O3 体系中的相关系
DOI：
10.1111/j.1151-2916.2002.tb00545.x
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发表时间：
2004
影响因子：
3.9
通讯作者：
M. Shimada
中科院分区：
文献类型：
--
作者：
N. Hirosaki;Yoshinobu Yamamoto;T. Nishimura;M. Mitomo;J. Takahashi;H. Yamane;M. Shimada
在1850°C、1 MPa N2气氛下研究了Si 3 N4-SiO2-Lu 2 O3体系的相关系.在Si 3 N4-SiO2-Lu 2 O3系统中，只有J相Lu 4Si 2 O 7 N2（单斜晶系，空间群P21/c，a = 0.74235（8）nm，B = 1.02649（10）nm，c = 1.06595（12）nm，β = 109.793（6）°）以氧氮化镥硅相存在。Si 3 N4/Lu 2 O3比为1，对应于M相组成，导致Lu-J相、β-Si 3 N4和新相Lu 3Si 5 ON 9的混合物，具有正交对称性，空间群Pbcm（No.57），其中a = 0.49361（5）nm，B = 1.60622（16）nm，和c = 1.05143（11）nm。新相在新的Si 3 N4-LuN-Lu 2 O3体系中表现得最好。相图表明，Lu 4Si 2 O 7 N2是氮化硅陶瓷中一种优良的高温晶界相。
Phase relationships in the Si 3 N 4 -SiO 2 -Lu 2 O 3 system were investigated at 1850°C in 1 MPa N 2 . Only J-phase, Lu 4 Si 2 O 7 N 2 (monoclinic, space group P2 1 /c, a = 0.74235(8) nm, b = 1.02649(10) nm, c = 1.06595(12) nm, and β = 109.793(6)°) exists as a lutetium silicon oxynitride phase in the Si 3 N 4 -SiO 2 -Lu 2 O 3 system. The Si 3 N 4 /Lu 2 O 3 ratio is 1, corresponding to the M-phase composition, resulted in a mixture of Lu-J-phase, β-Si 3 N 4 , and a new phase of Lu 3 Si 5 ON 9 , 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 Si 3 N 4 -LuN-Lu 2 O 3 system. The phase diagram suggests that Lu 4 Si 2 O 7 N 2 is an excellent grain-boundary phase of silicon nitride ceramics for high-temperature applications.