In:
Proceedings, annual meeting, Electron Microscopy Society of America, Cambridge University Press (CUP), Vol. 48, No. 1 ( 1990-08-12), p. 596-597
Abstract:
We observed the HREM images of extended dislocations in InP crystals and the effects of electoron beam on their configurations. InP crystals were grown by LEC method. The samples used for HREM observation were prepared by crushing technique. The observation was performed using a 4000EX HREM at 400KV with beam current density 10Pa/cm 2 and magnification 8×10. 5 The direction of observation is parallel to [110] zone axis of the specimen. It was found that there were a number of extended dislocations in InP crystal. They consist of two partial dislocations with Burgers vectors of 1/6[211] and l/6[121] and an piece of intrinsic stacking fault between them. Fig. 1. shows an extended dislocation observed. The contrast changes induced by the stress field of partial dislocations and the relative displacement of the lattice on the two sides of the stacking fault should be noted. The measurement show that the average width of extended dislocations in Inp crystal is about 155Å. The stacking fault energy estimated by the average width is about 170 ergs/cm 2 . Observation found that the extended dislocations might movei contract or further extend its width due to the electron beam irradiation during the HREM observation. Fig. 1. to 4. are the successive photographs of the same area. The interval between the two successive pictures is about 10 sec. The extended dislocation contracted continuously so that it became a nearly perfect dislocation with Burgers vector b=1/2[110l in Fig.4. It is obvious that the higher thermal stress induced by beam irradiation may produce the motion as well as the width changes of extended dislocations in InP crystal.
Type of Medium:
Online Resource
ISSN:
0424-8201
,
2690-1315
DOI:
10.1017/S0424820100181749
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1990
SSG:
11
