碳化硅的多型性

本文利用鉴定碳化硅多型体的“点间关系法”分析了一千一百多个碳化硅单晶体的劳埃照片。发现了61种碳化硅新多型体,其中六方晶胞c轴点阵常数最大的多型体1041R的点阵常数达2622.8?。至此碳化硅多型体的数目达110种,其中六方多型体30种,三方多型体80种。利用实验资料对现有的三种碳化硅多型体形成机理作了讨论,即1.螺型位错理论;2.生长环境因素理论和3.热力学理论。

THE POLYTYPISM OF SILICON CARBIDE

By using the method of point relation for identification of SiC polytype, more than 1100 Laue patterns of SiC single crystals were analysed and 61 kinds of new modifications of α-SiC were found, in which the largest lattice parameter of c-axis in the hexagonal unit cell is 2622.8?. So far the number of SiC polytypes reaches 110 kinds, in which the hexagonal polytypes are of 30 kinds and the rhombohedral polytypes are of 80 kinds.According to the experimental data, the three different mechanisms of forming the SiC polytypes at the present time were discussed:1) the screw dislocation theory,2) the growth condition theory,3) the thermodynamic theory.