The heat capacity of high-purity dysprosium from 0.5 to 20 K

Measurements have been made on a two single-crystal specimens of high purity dysprosium. After heat treatment to remove hydrogen, the specimens give identical results. Analysis shows that there may still be small (1%) effects due to hydrogen, and this is the main cause of uncertainty in the deduced values of the electronic specific heat coefficient gamma =4.9+or-0.1 mJ K -2 mol -1 and the Debye temperature in the low temperature limit theta 0 =192+or-2 K. At the higher temperatures the magnetic contribution accounts for about half the total specific heat, and its temperature dependence can be represented by an expression of the form AT" exp(-E g /kT). For n=1.5 it is found that E g =26 K, but other pairs of n and E g fit equally well.