Complexity of hexagonal approximants in the RE13Zn~58 system (RE = Ce, Pr, Nd, Sm, Gd, Tb and Dy)

✍ Scribed by Piao, Shuying; Pay Gómez, Cesar; Lidin, Sven

• Book ID: 120644702
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 2006
• Tongue: English
• Weight: 532 KB
• Volume: 221
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.2006.221.5-7.391

✦ Synopsis

Abstract

For the RE
~13~Zn~58~quasi crystal approximants (RE = Ce, Pr, Nd, Sm, Gd, Tb, Dy), single crystals were prepared from the elements and their structures were refined from single-crystal X-ray diffraction data. They are derived from the Gd~13~Cd~58~type structure and crystallize in the space group __P__6~3~/mmc or its subgroups. The crystal structures of Ce and Pr compounds are identical to that of the archetype, in the Nd compound a pair exchange disorder changes the composition and for Sm a further, partially occupied interstitial position lowers the symmetry to __P__6~3~
mc. For the compounds with Gd, Tb and Dy, the occupancy may order, lowering the symmetry further. For the case of Tb~13~Zn~59~ high quality single crystals allowed us to refine the fully ordered orthorhombic super structure.