Electron Diffraction Contrast of Small Stacking Fault Tetrahedra with Applications to Quenched Gold

It is shown that the characteristic diffraction contrast of small stacking fault tetrahedra obtained by imaging with a {220} reflection can be used to distinguish small unresolved stacking fault tetrahedra from dislocation loops. Application of these results to quenched gold shows that vacancy clusters exist already in their early stage as stacking fault tetrahedra.