The effect of tin alloying on the structure of LaNi5

This work investigates the effect of tin on the structure of LaNi5. LaNi5Snx (x=0-0.06) alloy powders were prepared by ball milling LaNi5 and tin, followed by annealing. On the basis of X-ray diffraction analysis both lattice parameters a and c in the hexagonal LaNi5-ySny structure increase with increasing tin content to a maximum at y=0.44. Tin additions in excess of this amount cause no further changes in the lattice parameters and new Bragg peaks corresponding to LaNi5Sn are present in the X-ray data. Rietveld analysis performed on four alloys LaNi5Snx (x=0.1, 0.2, 0.3 and 0.4) indicate that tin occupies only the 3g sites in the LaNi5 structure.