Possible Evidence for Overcoordination at Semiconductor Grain Boundaries

The structure of a near coincidence Ge tilt grain boundary, containing a step, has been derived from a high resolution electron micrograph. There are two possible interpretations of portions of this interface, one of which is the existence of a sheet of fivefold coordinated atoms between the Σ = 19 and Σ= 27 coincidence misorientations. This finding may represent the first experimental evidence that overcoordinated atoms are present at semiconductor grain boundaries free of a screw dislocation. © 1990, Materials Research Society. All rights reserved.