氮化铝晶须的形态和结晶方向

MORPHOLOGY AND CRYSTALLOGRAPHY OF ALUMINIUM NITRIDE WHISKERS

在Ａｌ２Ｏ３Ｃ系统中添加一定量的ＣａＦ２和ＮＨ４Ｃｌ，在通氮气的高温炉中于１４５０℃经２ｈ的碳热还原氮化处理，制备出ＡｌＮ晶须。对该条件下制备的ＡｌＮ晶须进行了分析，结果表明：晶须的形态有直板状、弯曲、分叉及波浪状等几种特征，其长径比差别较大，晶须的尺寸不均匀且部分的表面质量较差。透射电子衍射分析晶须的生长方向为［０１１２］和［１１０１］，其生长机制为ＶＬＳ机制。

AlN whiskers were composed by the Al 2O 3 C system with some CaF 2 and NH 4Cl addtion under the condition of carbothermal reduction treatment of 1 450 ℃ and 2 h as well as nitrogenous atmosphere. The composed AlN whiskers were analysed by XRD and TEM. The results showed that some whiskers' morphologies, such as plate curved, branched corrugated, were observed and the ratio of length to diameter changed greatly; the composed whiskers are not even, some surface quality is not high. TEM analyses showed that the fiber axes are normal to 12] and 101]. The mechanism of the whiskers growth was supposed to be VLS(Vapor Liquid Solid).