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Title: The effect of plastic deformation on the electrical properties of indium antimonide
Author: Willoughby, Arthur Frank Wesley
Awarding Body: University of London
Current Institution: Imperial College London
Date of Award: 1965
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A study was made of the effect of plastic deformation on the electrical properties of indium antimonide. Single crystal specimens oriented for single slip were plastically bent to introduce an excess of dislocations having either In-atoms at the edge of their extra halfplanes (In-dislocations) or having Sb-atoms there (Sb-dislocations). Plastic bending at a constant strain rate was characterised by a sharp yield point followed by a region of constant stress where single slip predominated. The lower yield stress for bending at 270°C was dependent on the direction of bend, being greater when specimens were bent to produce an excess of Sb-dislocations than when they were befit to produce an excess of In-dislocations. This may be due either to the glide mobility of In-dislocations being greater than that of Sb-dislocations, or to the more rapid climb of the former. The reliability of etching reagents in revealing dislocations as etch-pits was tested by a series of bending and annealing experiments. It was shown that one type of etchant attacks In-dislocations preferentially. Another etchant was found to give a reliable estimate of the total density of dislocations present. The electrical properties of dislocations were investigated by Hall coefficient and electrical conductivity measurements on bent samples. It was found that both In- and Sb-dislocations act as acceptor centres in n-type material. The conductivity of bent samples was highly anisotropic indicating that the dislocations were lying predominantly parallel to the bend axis. The results were analysed in terms of two models, and, in each case, an energy level in the forbidden gap was assigned to each type of dislocation.
Supervisor: Bell, R. L. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available