Domain structures of tetrahedrally close-packed phases with juxtaposed pentagonal antiprisms I. Structure description and HREM images of the C14 Laves and μphases

Abstract

Zr₄Al₃ has a deformed 4⁴ and MgCu₂ a deformed 3⁶ net of juxtaposed pentagonal antiprisms. A family of tetrahedrally close-packed structures can be derived based on these fundamental units. Various possibilities for intergrowth of the C14 Laves and μ phases are discussed. It is shown that each pentagonal antiprism in these phases can be imaged as a bright spot in a high resolution image, and the imaging conditions for interlaced C14 Laves and μ phases have been found.