Electron diffraction study on ε superstructure in the compound layer of ion-nitrided pure iron

The epsilon-Fe2-3N nitrides in the compound layer of ion-nitrided pure iron were studied with transmission electron microscopy. A superlattice with lattice parameters (a" = 2aroot3 = 0.9294 nm, c" = c = 0.4382 run) bigger than those of epsilon hexagonal close packed unit (a = 0.2683 nm, c = 0.4382 nm), which was tentatively named as epsilon" superstructure, was investigated by electron diffraction method. A series of its diffraction patterns were recorded and the diffraction intensity was analyzed. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.