自蔓延高温合成LaB_6微粉的制备及表征

Preparation of LaB_6 Micropowder by Self-Propagating High-Temperature Synthesis and Characterization

采用自蔓延方法制备出LaB6微粉·对热爆产物和浸出产物进行X射线衍射分析,确定了两步酸浸方案·对LaB6进行TEM分析和光谱分析,并利用扫描电镜(SEM)和粒度分布测试仪对LaB6进行了表征·结果表明:热爆产物由LaB6,MgO,少量Mg3B2O6以及LaOCl等相组成,采用盐酸和硫酸两步交叉浸出获得纯净的单一相LaB6·计算得LaB6晶格常数a=0 4148nm,LaB6纯度大于99%,LaB6的平均粒径为1 92μm·

LaB_6 micropowder was prepared by self-propagating high-temperature synthesis(SHS). SHS process in which the thermally explosible and leachable products were checked by XRD, then a two-step leaching procedure was therefore confirmed. The LaB_6 prepared was analyzed and characterized by TEM, spectral analysis, SEM and granularity analyzer. The results indicated that the thermally explosible products consist of LaB_6, MgO and bits of Mg_3B_2O_6 and LaOCl, and that the single pure phase LaB_6 can be obtained using HCl then H_2SO_4 in an interlacing way in leaching process. The crystal lattice constant of LaB_6 was calculated as a=0.4148nm, with its purity lower than 99% and the mean grain size is 1.92μm.