THE EFFECT OF TIN ALLOYING ON THE STRUCTURE OF LANI5

This work investigates the effect of tin on the structure of LaNi5. La Ni5Snx (x=0-0.06) alloy powders were prepared by ball milling LaNi5 an d tin, followed by annealing. On the basis of X-ray diffraction analys is both lattice parameters a and c in the hexagonal LaNi5-ySny structu re increase with increasing tin content to a maximum at y=0.44. Tin ad ditions in excess of this amount cause no further changes in the latti ce parameters and new Bragg peaks corresponding to LaNi5Sn are present in the X-ray data. Rietveld analysis performed on four alloys LaNi5Sn x (x=0.1, 0.2, 0.3 and 0.4) indicate that tin occupies only the 3g sit es in the LaNi5 structure.