Novel Rare Earth Boron-Rich Solids

✍ Scribed by Fuxiang Zhang; Andreas Leithe-Jasper; Jun Xu; Takao Mori; Yoshio Matsui; Takaho Tanaka; Shigeru Okada

• Book ID: 102610614
• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 412 KB
• Volume: 159
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9147

✦ Synopsis

A new series of boron-rich solids ReB 22 C 2 N (Re: Y, Ho, Er, Tm, Lu) were synthesized by traditional solid-state reaction. The crystal structure of the representative compound YB 22 C 2 N was solved by direct method from powder X-ray di4raction (XRD) data and transmission electron microscope (TEM) analysis. The unit cell of the new structure is rhombohedral with space group R-3m (No. 166), lattice constant a ‫؍‬ b ‫؍‬ 5.623(0) A s and c ‫؍‬ 44.785(3) A s with six formula units in one unit cell. The atoms of boron in the solids, like most of the boron-rich solids, exist with icosahedral and octahedral clusters, and the whole crystal shows a layered structure. The interconnected nine layers of icosahedron and three layers of octahedron in a unit cell build the whole framework of the new phase and rare earth metal atoms reside in voids of the octahedron layers. The neighboring icosahedral layers link through C+B+C chains besides the direct bonding of B+B. Both experimental and structural analysis indicated that the nitrogen atoms in the new phase can be replaced with carbon.