掺B对制备纳米SiC的影响  

Effect of Boron on the Preparation of Nano-SiC

作　　者：喻冲[1] 周大利[1] 郑卓[1] 胡驰[1] 刘松[1] 

机构地区：[1]四川大学材料科学与工程学院,成都610064

出　　处：《材料导报（纳米与新材料专辑）》2012年第1期77-79,共3页

摘　　要：以正硅酸乙酯和葡萄糖分别作Si源和C源,草酸和硼酸分别作催化剂,采用溶胶-凝胶法制备SiC前驱体,并采用碳热还原法制备纳米SiC。采用XRD、SEM对样品的物相和形貌进行表征。结果表明,用草酸作催化剂制备的前驱体在1550℃制备的SiC是颗粒与晶须的混合体,颗粒粒径为30～50nm,晶须长度为1～3μm,晶须直径为60～100nm;用硼酸作催化剂制备的前驱体其碳热还原温度显著降低,在1400℃就能制备出SiC颗粒与晶须的混合体,颗粒粒径为20～30nm,由于B加入后的抑制作用,SiC晶须的含量明显减少。By using tetraethoxysilane（TEOS） and dextrose as the silicon source and carbon source, respective ly, and oxalic acid and boric acid as catalyst, SiC precursor was produced by sol gel method. Then nano-SiC was syn thesized through the carbothermal reduction reaction of the precursor. XRD and SEM were used to characterize the sanlple＇s phase and morphologies. The results show that SiC, produced under 1550℃ by the precursor which is pro duced by using oxalic acid as catalyst, is the mixture of SiC grain and SiC whiskers. The diameter of grain is 30 50nm, the length of whisker is l^3μm and the diameter of whisker is 60~ 100nm. The carbothermal reduction reac tion temperature of precursor reduced significantly, produced by using boric acid as catalyst and the mixture of SiC grain and SiC whiskers can be produced under 1400℃. The diameter of grain is 20~30nm. SiC whisker reduced oh viously due to the inhibition after adding tA.

关 键 词：碳化硅 草酸 硼酸 晶须 

分 类 号：TQ426.6[化学工程]