3-STEP MAGNETIC PHASE-TRANSITION IN NDCU2 AS STUDIED BY NEUTRON-DIFFRACTION

We report the result of a study on the magnetic structure of NdCu2 by means of neutron diffraction. In contrast to the recent report of the powder diffraction study by Arons et al., we detected three magnetic p hases, one new in between the two that had been reported. This new pha se exists in the temperature range between 3.90 and 4.15 K, and these two temperatures agree quite well with the temperatures where the spec ific heat anomalies were observed in the recent experiment by Takayana gi et al. The magnetic structure of the new phase is represented by a modulation vector with a slightly temperature dependent incommensurate wave number. The typical value of the modulation vector is (0.603, 0. 0035, 0), which is very close to the one in the adjacent phase, i.e., (0.6, 0, 0).