Low-temperature heat capacity of electrotransport-purified scandium, yttrium, gadolinium, and lutetium

The low-temperature heat capacity of electrotransport-purified scandium, yttrium, gadolinium, and lutetium have been measured from 1 to 20 K. The electronic specific-heat constant {γ} and the Debye temperature CTHETAD are determined to be 10.334±{}0.011 mJ/g-at. K² and 354.3±{}1.0 K, respectively, for scandium, 7.878±{}0.004 mJ/g-at. K² and 244.4±{}0.5 K, respectively, for yttrium, 6.380±{}0.026 mJ/g-at. K² and 163.4±{}0.1 K, respectively, for gadolinium, and 8.194±{}0.016 mJ/g-at. K² and 183.2±{}0.3 K, respectively, for lutetium. We believe that the above electronic specific-heat constants and Debye temperatures represent the intrinsic values for these four rare-earth metals. The use of the low-temperature heat-capacity results for these metals to evaluate the various contributions to the heat capacities of the magnetic lanthanide metals is examined. The total many-body enhancement factor and its components (the electron-phonon, electron-paramagnon, and spin-wave) are calculated.