Structural variations in ϵ-type Al–Pd–(Mn, Fe) complex metallic alloy phases

Abstract

Structural modifications in complex metallic ε-Al–Pd–(Mn, Fe) samples were studied by means of transmission electron microscopy. The modifications were observed in the vicinity of metadislocations and at phase boundaries. They are determined by the density and inclination of phason planes. In the vicinity of metadislocations and at an ε₆–ε₂₈ phase boundary, new monoclinic ε-type structures appear locally, which had not been detected as bulk phases in Al–Pd–(Mn, Fe) previously. The present work points out the close entanglement between defects, i.e. metadislocations and phason planes, and structural modifications in ε-type complex metallic alloys. An extended classification of ε-type phases including monoclinic phases is presented on the basis of two different tiling descriptions.

Acknowledgments

We thank Dipl.-Ing. C. Thomas and M. Schmidt for the materials production. This work was supported by the Deutsche Forschungsgemeinschaft (PAK 36), and the 6th Framework EU Network of Excellence “Complex Metallic Alloys” (Contract No. NMP3-CT-2005-500140).