Spin density wave antiferromagnetism in dilute Y1-xDyx alloys

The specific heat c and the magnetic susceptibility χ of three YDy alloys with concentrations ranging from 2.5 to 4.5 at% Dy have been measured in the temperature range 5 to 25 K. Beside a large Schottky anomaly corresponding to the crystal field splitting of the Dy groundstate, c shows a well defined maximum at thesame temperature as a peak in the susceptibility. These results tend to rule out a spin-glass freezing and suggest long range antiferromagnetic ordering, probably due to the existence of spin density waves. (orig.)