Crystal Structures of the LnAlSi and LnAlGe Compounds.

Abstract

Structure Structure D 2000Crystal Structures of the LnAlSi and LnAlGe Compounds. -Samples of LnAlSi with Ln: Y, Dy, Ho, Er, Tm, and Lu are prepared by arc melting of the elements and homogenization at 873 K (evacuated quartz tube, 500 h, quenching). The terbium alumosilicide TbAlSi crystallizes in the tetragonal α-ThSi2-type structure (space group I41/amd). The compound has a narrow homogeneity range, TbAl1.05-0.99Si0.95-1.01. The compounds with Ln: Y, Dy, Ho, Er, Tm and Lu crystallize with orthorhombic YAl-Ge-type structures (space group Cmcm) with constant composition. The structures of all known LnAlSi compounds are characterized by trigonal-prismatic coordination of the smaller atoms. -(PUKAS, S.; LUTSYSHYN, Y.; MANYAKO, M.; GLADYSHEWSKII*, E.; J. Alloys Compd. 367 (2004) 1-2, 162-166; Dep. Inorg. Chem., Ivan Franko Natl. Univ. L'viv, L'viv 79005, Ukraine; Eng.) -Schramke 26-012