Crystal structure of LaNi5Sn

The crystal structure of the LaNi5Sn intermetallic compound has been studied by means of synchrotron powder X-ray diffraction at 293 K. LaNi5Sn crystallises with the hexagonal CeNi5Sn type (space group P63/mmc; a = 4.95809(4) Å; c = 19.9437(3) Å) with two crystallographic sites occupied by La, four jointly by Ni and Sn, and one solely by Ni. A characteristic feature of the structure is the significant mutual substitution of Ni and Sn, which reaches a maximum of 45% for the substitution of Ni for Sn. The distribution of Ni and Sn in the structure of LaNi5Sn is different from those reported for CeNi5Sn [O. Moze, W. Kockelmann, E. Brück, K.H.J. Buschow, J. Alloys Compd. 279 (1998) 110]. The coordination polyhedra of the constituent atoms contain 18-20 vertexes for La; 14 vertexes for Sn/Ni and 10-13 vertexes for Ni and Ni/Sn sites.