Giant magnetostriction hysteresis in submicrocrystalline dysprosium and annealing effects

A study is made into the influence of structural state on the shape of magnetostriction hysteresis loop in dysprosium. It is revealed that in submicrocrystalline state the shape of hysteresis loop of giant magnetostriction is the same as in ferromagnets up to the temperature of magnetostriction disappearance. The annealing at 573 K results in the appearance of the hysteresis loop at 120 K, suggested that helical antiferromagnetic order occurs. In the intermediate structural state the coexistence of ferromagnetic and antiferromagnetic orders is observed. The hysteresis loop shape of coarse-grained dysprosium corresponds to ferromagnets at 78 K and to antiferromagnets at 100 K. 10 refs., 4 figs