The Mechanism of Deformation of the Ordered CuAu Alloy

Abstract

Electron microscopy techniques are used t o study the domain structure and the mechanism of deformation of the ordered CuAu alloy. Investigations are made into the factors impeding the passage of dislocations across the boundary between domains with differently orientated c-axes. Experiments indicate that the greatest obstacle to the passage of dislocations across such a boundary is the necessity of pairing single dislocations.Mit elektronenmikroskopischen Methoden werden Untersuchungen der Domiinenstruktur und des Deformationsmechanismus in geordneten Cu-Au-Legierungen durchgefuhrt. Die Faktoren werden untersucht, die den Durchgang von Versetzungen durch die Grenzen zwischen Domiinen mit verschieden orientierten c-Achsen verhindern. Die Ergebnisse zeigen, dafl das Haupthindernis fur den Durchgang von Versetzungen durch eine solche Grenze die Notwendigkeit ist, dafl sich die Einzelversetzungen zu Paaren zusammenschlieflen.

Hierarchical domains in Na1/2Bi1/2TiO3 single crystals: Ferroelectric phase transformations within the geometrical restrictions of a ferroelastic inheritance

“…13 With increasing x, piezoforce microscopy ͑PFM͒ and polarized light microscopy ͑PLM͒ investigations have shown 14,15 that these polar nanoregions self-assemble into small domain striations along the ͗110͘ that are submicron sized, which subsequently geometrically organize into large ͕100͖ platelets or bands of about 100 m in size. These hierarchical domain organizations are similar to those of martensite 16,17 where such arrangements achieve stress accommodation relaxing the elastic energy. However, in-spite of the relaxor analogy for the R phase of NBT, neither the presence of polar nanoregions nor hierarchical domains has yet been reported.…”

Adaptive ferroelectric states in systems with low domain wall energy: Tetragonal microdomains

“…1͑b͒. 6 The black and white stripes in this transmission electron microscopy ͑TEM͒ image are alternating twin-related domains of the tetragonal phase. These stripes assemble into macroplates of the kind shown in Fig.…”

Domain engineered states over various length scales in (001)-oriented Pb(Mg1∕3Nb2∕3)O3-x%PbTiO3 crystals: Electrical history dependence of hierarchal domains

“…8. 28 The twin boundaries of the fingerprints are not restricted to be 180°. Self-assembly is achieved by varying the relative domain layer thicknesses of the fingerprints, which are adjusted to establish the macroscopic invariance of the habit plane, 29,30 and in doing so eliminating the long-range stress fields generated by crystal lattice misfits.…”