Crystal Structure and Vibrational Spectra of Li2BAlO4

✍ Scribed by V. Psycharis; I.A. Kapoutsis; G.D. Chryssikos

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 297 KB
• Volume: 142
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1998.8037

✦ Synopsis

The structure of Li 2 BAlO 4 is solved ab initio by a powder X-ray diffraction technique. The unit cell of this metaboroaluminate compound is monoclinic (space group P2 1 /c, a‫)3(0272.6؍‬ A s , b ‫؍‬ 5.0701(3) A s , c ‫؍‬ 10.2989(6) A s , ‫,°)2(288.59؍‬ Z ‫؍‬ 4, calc ‫؍‬ 2.36 g/cm 3 ). Its network consists of infinite chains of metaaluminate tetrahedra, which are cross-linked by metaborate triangles in a way that leads to the formation of B 2 Al 2 O 4؊ 8 rings. These anionic groups are charge-balanced by two crystallographically distinct pairs of four-coordinated lithium ions. The infrared and Raman spectra Li 2 n BAlO 4 and Li 2 10 BAlO 4 are reported, and the assignments of their main features are discussed in light of the spectra of relevant compounds. Vibrational spectroscopic tools for the identification of mixed metaboroaluminate network sequences are proposed.