New ternary compound La8Al13Sn3

A new ternary compound La8Al13Sn3 was synthesized and studied by means of X-ray powder diffraction technique. The compound La8Al13Sn3 crystallizes in a hexagonal AlB2-type structure with space group P6/mmm (No. 191) and the lattice parameters a = 0.44919(1) nm and c = 0.43835(1) nm. The Smith and Snyder figure of merit for index, F N , is F 30 = 197.3(30). The Rietveld refinement for the crystal structure of the compound was carried out successfully. The liability R-factors of Rietveld refinement are R p = 0.114 and R wp = 0.148. The compound La8Al13Sn3 decomposes into LaAl2 with cubic structure and space group Fd \( \bar 3 \) m (227), LaAl3 with hexagonal structure and space group P63/mmc (194), and Sn at 720°C.