Dislocation dissociation in stoichiometric MgAl₂O₄spinel observed by weak-beam electron microscopy

Abstract

Abstract Dissociation of dislocations in deformed stoichiometric MgAl,O4 spinel was observed, using weak-beam electron microscopy at 650 kV. The dissociation width was approximately 100 Å for dislocations near to edge orientation. The corresponding stacking fault energy was calculated to be 135 ± 20 erg/cm2. In comparison, the stacking fault energy of non-stoichiometric spinel is much lower and is estimated to be approximately 45 and 21 erg/cm2 for compositions of Al2O3/MgO = 1·5 and 3·5, respectively.