Atomic structure of {112} Σ = 3 twin boundary in β–SiC

Centre de Microcaractérisation, Laboratoire de Physique Cristalline, Institut des Matériaux de Nantes, B.P. 32229, 44322 Nantes Cedex 3, France

Received: 24 June 1998
Revised: 13 October 1998
Accepted: 5 November 1998
Published online: 15 February 1999

Abstract

We study the atomic structure of twin boundaries consisting of a stacking of six planes and characterized by a resulting Burger vector equal to zero. The twins were imaged by HRTEM. We develop image processing to localize the silicon and carbon atoms in each grain and thus to deduce their stacking and to calculate the possible rotation and translation of one grain with respect to the other with an accuracy greater than 0.1%. We show that there is no rigid body translation between the two grains. However, models derived from Möller or Pond et al. are not suitable. We propose an alternative model which is in close agreement with the asymmetrical contrast of the twin boundary.