Magnetostriction of Laves Phase Rare Earth-Ni2 Compounds

摘要

The magnetostriction of the RNi2 compounds (R = Tb,Dy,Ho,Er and Tm) was measured as a function of applied field from T = 5 K to above the Curie temperatures. A direct comparison is made between these results and the huge magnetostriction observed at cryogenic temperatures in the RFe2 and RCo2 compounds. The largest magnetostriction in the RNi2 series occurs in TbNi2. At T = 5 K the magnetostriction is fairly well saturated and results in a value of Lambda sub H - Lambda sub T = .00227 at H = 25 kOe, while extrapolation to infinite field yields .00234. DyNi2 also displays a tendency to saturate at the higher fields at lower temperatures with Lambda sub H - Lambda sub T = -.000765 at 25 kOe and -840 ppm at H= infinity. The compounds HoNi2, ErNi2 and TmNi2 all exhibit large strains at T = 5 K although fail to saturate with available fields. At 25 kOe the magnetostriction for these compounds found to be -.000386, -.000415 and -.000552 respectively. (Author)