复杂结构单晶SADP的标定

Indexing SADP for Single Crystal with Complex Crystal Structure

摘要:

以钛合金中相的单晶选区电子衍射花样（ＳＡＤＰ）的标定为例，探讨了复杂结构单晶ＳＡＤＰ的标定。指出，对复杂结构的晶体可按其衍射条件从下述方法中选择一种对其单晶ＳＡＤＰ进行标定：１、按其所属布喇菲点阵用现有方法分析后直接标定；２、按适当布喇菲点阵用现有方法分析然后将结果进行数学变换后进行标定；３、对现有方法无法进行协定的复杂结构按其衍射条件对现有分析程序修改后（纯ｈｋｌ法）进行分析标定。当存在结构消光时，二次衍射对标定方法有影响：可分别用已有程序和修改后的程序对ＳＡＤＰ进行分析，然后选择正确的结果进行标定；理

Abstract:

he effect of complex crystal structures on indexing single crystal SADPs has been investigated on the base of the indexing SADPs of phases in titanium alloys. According to the structure, SADPs can be indexed by one of the following three methods: I .directly indexing SADP by analyzing result according to a Brayals lattice which the structure belongs to; 2.indexing the SADP by using the result gotten according to a suitable Brayals lattice and a necessary mathematical transformation a. indexing the SADP with result calculated with a computer program which was modified according to the diffraction condition of the structure.A pure hkl method in programming for analyzing the corn plex structure is presented to make the programming easier. In the condition of presenting a structure extinction,the SADP can be indexed with the result calculated with present program used foe Brayals lattices and the program modified according to the structure simultaneously. The ideal method for indexingSADPs is a program modified according to the diffraction condition, structure extinction and double d if fraction of a complex structure.