摘要
氮氧化硅(Si_2N_2O)难于直接从 Si_3N_4和 SiO_2中制取。因此加入少量氧化物添加剂,如 Al_2O_3、Y_2O_3或MgO 于 Si_3N_4和 SiO_2中,在1150～1800℃的温度范围内,对 Si_2N_2O 生成反应的动力学进行了研究。应用 X 射线衍射确定了反应产物。实验结果表明,氧化物添加剂导致液相形成,从而降低了反应的活化能,大大加速了 Si_2N_2O 的生成。生成反应可描述如下:Si_3N_4(c)+SiO_2((?))→2Si_2N_2O(c)Si_3N_4在液相中的溶解是控制性步骤。Si_2N_2O 生成动力学与 Si_3N_4在液相中溶解量的大小有关,与 Si_3N_4的晶型种类无关。Y_2O_3或 MgO 比 Al_2O_3添加剂更有利于 Si_2N_2O 的生成。
Silicon oxynitride,Si_2N_2O,is difficult to be fabricated directly from Si_3N_4 andSiO_2.Small amounts of oxide additives,such as Al_2O_3,Y_2O_3 or MgO,were thereforeadded into the mixture of Si_3N_4 and SiO_2,and the reaction kinetics of the formationof Si_2N_2O was investigated in the temperature range 1150 to 1800℃.The reactionproducts were determined by using X-ray diffraction.The experimental results indi-cate that the oxide additives can lead to the formation of liquid phase,thus lower-ing the reaction activation energy,and largely accelerating the formation of Si_2N_2O.The reaction can be described as follows:Si_3N_4(c)+SiO_2(1)→2Si_2N_2O(c).It isbelieved that the dissolution of Si_3N_4 in the liquid phase is a rate-limiting step.The kinetics for Si_2N_2O formation is dependent on the dissoluble amount of Si_3N_4in liquid phase and independent of the modification of Si_3N_4.The Y_2O_3 or MgOadditives can result in the formation of Si_2N_2O more favorably than Al_2O_3.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第4期422-429,共8页
Journal of Inorganic Materials
关键词
氮氧化硅
氧化物
助剂
液相反应
Silicon oxynitride
Oxide additive
Liquid phase reaction
Kinetics
Activation energy
