The CaAg2—CaZn2—CaAl2 pseudo ternary system: crystal structures and structural stability

✍ Scribed by Pani, Marcella; Fornasini, Maria L.; Merlo, Franco

• Book ID: 120659431
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 2007
• Tongue: English
• Weight: 136 KB
• Volume: 222
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.2007.222.5.218

✦ Synopsis

The CaAg~2~—CaZn~2~—CaAl~2~ pseudo ternary system has been studied by micrographic and X-ray diffraction analyses of 37 alloys, melted and annealed at 973 K or 873 K in tantalum crucibles. Single crystal and powder X-ray data show a distribution of the phases among four structure types: MgCu~2~, MgZn~2~, MgNi~2~ (the Laves phases) and CeCu~2~ (for the first time reported for KHg~2~). A good separation of the structural domains was obtained by means of a two-dimensional map based on the size and electronic factors. The different volume effects shown by the CeCu~2~-type phases as regards those of the Laves phases were accounted for on the basis of the hard-sphere space filling model.