The coloring problem in intermetallics: bonding and properties of Tb 3 Zn 3.6 Al 7.4 with the La 3 Al 11 structure type

✍ Scribed by Han, Mi-Kyung; Morosan, Emilia; Canfield, Paul C.; Miller, Gordon J.

• Book ID: 120631398
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 2005
• Tongue: English
• Weight: 316 KB
• Volume: 220
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.220.2.95.59124

✦ Synopsis

Abstract

Single crystals of the new compound Tb~3~Zn~3.6(1)~Al~7.4(1)~ were obtained from Al and Zn-rich ternary solutions. The title compound crystallizes in the orthorhombic La~3~Al~11~ structure type (space group Immm (No. 71), Z = 2; a = 4.2334(1) Å, b = 9.9725(3) Å, c = 12.4659(1) Å). The inverse susceptibility above ca. 50 K shows Curie-Weiss behavior, and a metamagnetic transition is apparent in the T = 2 K field-dependent magnetization around H~c~ ∼ 20 kG. The resistivity increases with temperature in a roughly linear fashion, indicating the metallic character of this material. TB-LMTO-ASA electronic structure calculations indicate that this new intermetallic phase has all bonding states optimized in the [Zn~4–x~Al~7+x~] network, which classifies this compound among the so-called “polar intermetallics”. The calculations also provide a rationalization of the nonrandom ordering of Zn and Al atoms, which can be attributed to optimizing (Zn, Al)—(Zn, Al) orbital interactions.