Magnetostriction of Laves phase rare earth-Ni2compounds

The magnetostriction of the RNi2compounds (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 RFe2and RCo2compounds. The largest magnetostriction in the RNi2series occurs in TbNi2. At T = 5 K the magnetostriction is fairly well saturated and results in a value of at H = 25kOe, while extrapolation to infinite field yields . DyNi2also displays a tendency to saturate at the higher fields at lower temperatures with at 25kOe and -840 ppm at . The compounds HoNi², ErNi2and TmNi2all exhibit large strains at T = 5 K although fail to saturate with available fields. At 25kOe the magnetostriction for these compounds was found to be and respectively.