LACBED study of a Sigma 3 grain boundary in a Cu plus 6 at% Si alloy

A new application of the large-angle convergent-beam electron diffraction t echnique for the determination of the displacement vector R at a Sigma 3 gr ain boundary in Cu + 6 at% Si alloy is presented here. It is shown that in large-angle convergent-beam diffraction many high-index reciprocal coincide nt site reflections, g(c), can be utilized to obtain the phase factor of g( c).R, allowing a high accuracy for the determination of R. In this study th e value of R at an asymmetric boundary of (1 2 1)/(5 2 5) in a ((1) over ba r 2 (1) over bar) twin is accurately determined. This result indicates that there is no excess volume at this boundary. (C) 1999 Published by Elsevier Science B.V. All rights reserved.