The Al–Li–Si System: 1. A New Structure Type Li8Al3Si5 and the Ternary Solid-State Phase Equilibria

✍ Scribed by D. Kevorkov; J. Gröbner; R. Schmid-Fetzer

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 236 KB
• Volume: 156
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.9030

✦ Synopsis

Solid-state phase equilibria of the ternary Al+Li+Si system were studied by arc-melted and levitation-melted samples in the as-cast state and annealed at 2503C up to 1 month. Phase analysis was done with X-ray powder di4ractometry. The ternary phase diagram at 2503C is established. Three virtually stoichiometric ternary phases exist: LiAlSi ( 1 ), Li 5.3 Al 0.7 Si 2 ( 2 ), Li 8 Al 3 Si 5 ( 3 ). The phase 3 is a new compound, whereas 1 and 2 have also been reported in previous works. Other phases claimed in the literature do not exist in the stable phase diagram. The single crystals of the new ternary 3 compound were studied to determine their compositions by SEM/EDX. The crystal structure of the 3 compound was resolved using its similarities to LiAlSi structure and re5ned using Rietveld analysis. It is found that the Li 8 Al 3 Si 5 compound constitutes a new structure type with space group P4 3m and Pearson symbol cP16. Its unique features compared to closely related structure types are discussed.