%0 Journal Article
%T A STUDY OF ETCH-FIGURES OF DISLOCATION LINES IN MOLYBDENUM CRYSTALS<br>钼晶体中的位错线蚀象的研究
%A FONG DUAN
%A MING NAY-BEN
%A LI CHI
%A <br>冯端
%A 闵乃本
%A 李齐
%J 物理学报
%D 1964
%I 
%X Experimental results about dislocation etch-pits on {100}, {111}, and {110} surfaces of electron beam floating zone-melted molybdenum single crystals are described. Electrolytic etching reagents used in this work are mixtures of methyl alcohol, sulphuric acid, and chloric acid. Besides, etch-lines arranged in parallel sets and hexagonal networks are observed on {111} and {110} surfaces, these are interpreted as etch-figures of dislocation lines.An empirical rule for the interpretation of etch-figures of dislocation lines is deduced from observations. Observed etch-figures are projections on observation plane of dislocation lines in the etched layer, its widths depend on the distance between dislocation line-elements and original surface, so that an exaggerated perspective effect is obtained. Hence the arrangements of dislocation lines in space may be deduced directly from observed etch-figures. By means of multiple etching technique, some examples of dislocation arrangements in space are presented.Correspondance between etch-pits and sites of dislocation lines intersecting original surface has been studied. In general, such correspondance is observed by means of an etching-polishing-reetching technique. However, experimental results show that such correspondance may be violated in some cases. For instance, when the angle between a dislocation line and observation plane is less than a critical value (15°-24°), no etch-pit is observed. On the other hand, nodes of dislocation networks after prolonged etching, may be revealed as arrays of etch-pits. The significances of these results on the interpretation of etch-pits figures are discussed.The etch-figure method has been compared with other methods of direct observation of dislocation lines, its merits and demerits are discussed, and it is concluded that the etch-figure methods is superior to all other existing methods in the study of dislocations in metal crystals when the dislocation density is within the range from 104 to 108 cm-2.
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=29DF2CB55EF687E7EFA80DFD4B978260&aid=FBF001F437E1D96F&yid=29B68C6EE36B014B&vid=A04140E723CB732E&iid=E158A972A605785F&sid=5FF9F4F7CB1800C7&eid=381FB4265090A8E0&journal_id=1000-3290&journal_name=物理学报&referenced_num=0&reference_num=0