Synthesis and Crystal Structure Determination of LaAuO3

✍ Scribed by Martina Ralle; Martin Jansen

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 248 KB
• Volume: 105
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1228

✦ Synopsis

A new ternary oxide of gold and lanthanum, (\mathrm{LaAuO}{3}), has been prepared from (\mathrm{Au}{2} \mathrm{O}{3} \cdot 2 \mathrm{H}{2} \mathrm{O}) and (\mathrm{La}(\mathrm{OH}){3}) by applying high oxygen pressure and adding aqueous (\mathrm{KOH}(55 %)) as a mineralizer. The bright yellow and diamagnetic (\mathrm{LaAuO}{3}) crystallizes in the orthorhombic crystal system, (P b c m, a=) 403.35(7), (b=1307.3(2), c=569.52(8) \mathrm{pm}, Z=4). The crystal structure (determined from 980 unique reflections with a final (R) value of (\left.5.7 %\left(R_{\mathrm{w}}=4.7 %\right)\right)) consists of a grid of cubes formed by the oxygens which are either centered by lanthanum ions or face centered by gold ions. Thus, lanthanum is coordinated eightfold, and gold fourfold, by oxygen. (\mathrm{LaAuO}{3}) may be described as a (\mathrm{CaF}{2}) structure sheared within the (110) plane by half a translational period along ((00) 1). O 1993 Academic Press. Inc.