In-situ X-ray diffraction study on LaNi5 and LaNi4.75Al0.25 in the initial activation process

Single crystals of the DyMn2 compound were grown by the Czochralski method from a levitated melt. The electrical resistivity exhibits a magnetic transition at 40 K, a second transition at 25 K, a cubic temperature dependence at low temperatures and a saturation effect above 250 K. The magnetization in strong magnetic fields, and the DC and AC magnetic susceptibility measured along the principal crystallographic directions show an ordering of the dysprosium moments to a spin-canted magnetic structure at about 40 K and a spin reorientation below 25 K. The temperature dependence of the lattice parameter shows a lattice contraction below 40 K.