Nucleation and Growth of Inversion Domains in AIN: Part I, Study of Fundamental Processes

Inversion domains (IDs) are frequently observed in sintered AIN ceramics. In the present study, different stages of ID formation and growth were analyzed by transmission electron microscopy. A model was derived to describe the mechanisms of ID nucleation, growth, and interaction with dislocations. Accordingly, IDs are nucleated by wide inverted dislocation dissociations. Preexisting dislocations interact with moving ID boundaries (IDBs) by a mechanism of dissociation and integration into the IDE. The defect structures at IDBs are characterized by the inversion, a translation R = 1/3(1 1 00) corresponding to Shockley partials, and a translation R = w·[0001] perpendicular to the basal plane. The results are fundamental for further experiments of artificial generation or annihilation of IDs.