Stacking-Fault Energies of GaAs

Abstract

Transmission electron microscopy is used to determine the dissociation width of extended dislocations in n‐, si‐, and p‐GaAs. Results obtained by high‐resolution transmission electron microscopy (HRTEM) and the weak‐beam technique (WB) are compared. Reasons for the differences between the results obtained from WB and HRTEM and their influence on the determination of the stacking‐fault energy are discussed. The results are compared with previous investigations, which show a wide scatter of results despite the fact, that the stacking‐fault energy is an intrinsic material property. A number of parameters, such as the defect used for the determination, localization of the partial‐dislocation cores and the electrical characteristics of the material are considered to explain the discrepancies.

High-resolution electron-microscopy study of 60°-Dislocations in Cu

“…The locations of the 90"-and 30"-partials are marked. As pointed out by Gerthsen and Carter [21], the exact core position of 90"-dislocations cannot be determined as accurately as the 30"-partial core. Nevertheless, it is much more precise than the location as determined by the weak-beam technique.…”

“…More recently, Gerthsen and Carter [21] have compared WB results on GaAs with HRTEM observations and have found fair agreement between the two methods. Since the WB technique can be applied to foil thicknesses of several 100 nm, these results indicate that at least in the case of GaAs the surface effects are negligible.…”

Structure and energy of the partial dislocation cores in GaAs

“…The ISF energy is calculated using a 36 atom cell [38]. The calculated energy of 47 mJ/m 2 is in excellent agreement with the measured value of 44.9 ± 8 mJ/m 2 [39]. By direct comparison to atomic resolution microscopy images, it is know that in the vicinity of dislocation VASP predicts the atomic structure to better than 8 pm accuracy [10].…”

Stacking fault energies in austenitic stainless steels

“…It depends on the value of the excitation error, the depth of the dislocation within the foil and the sample thickness. Therefore, the measured dissociation width d obs must be corrected by the following weak-beam formula [48,49].…”