The specific heats of LaAg, GdAg and Gd₂O₃from 0.5 to 22K

Abstract

Specific heat measurements on monoclinic Gd2O3 show a cooperative peak at 3.8K. The entropy associated with this peak is the full 2R ln 8 expected for the Gd3+ ions. Measurements on GdAg are affected by the presence of small inclusions of Gd2O3, but it proves possible to allow for these and to deduce values for the electronic specific heat constant gamma which is 11.4+or-1.7 mJ mol.-1 K-2. For LaAg, gamma =9.9+or-0.2 mJ mol.-1 K-2. The lattice heat capacities are analysed in terms of a Debye temperature which is found to vary strongly with temperature; the low-temperature limiting values are 208K and 150K for GdAg and LaAg respectively.