Premium
High‐resolution electron microscopic study on long‐period superstructures with 6 H stacking sequence in Au 3 Cd alloys
Author(s) -
Lee K. H.,
Shindo D.,
Hiraga K.,
Hirabayashi M.
Publication year - 1990
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889889011441
Subject(s) - stacking , period (music) , sequence (biology) , materials science , electron microscope , crystallography , electron , high resolution , resolution (logic) , chemistry , optics , physics , geology , computer science , organic chemistry , acoustics , biochemistry , remote sensing , quantum mechanics , artificial intelligence
Atomic arrangements of long‐period superstructures in Au–24.5at.%Cd alloy with the basic h.c.p. structure have been investigated by high‐resolution electron microscopy. The alloy shows one‐dimensional or two‐dimensional long‐period superstructures in the close‐packed plane with a 6 H stacking sequence, depending on heat treatments. It is shown that the two‐dimensional incommensurate superstructure with a period larger than 9 a 0 is composed of domains of the hexagonal commensurate structure ( M = 9) separated by the antiphase‐boundary zone in which 3 3/2 a 0 × 2 a 0 × 3 c 0 orthorhombic structure is formed ( a 0 , c 0 being the lattice parameters of the h.c.p. structure). Microstructures of the alloy annealed at 620 K with the one‐dimensional long‐period superstructure and of the alloy quenched from 770 K showing diffuse scattering have also been investigated by high‐resolution electron microscopy.