Analysis of the Molar Specific Heat of Pr_1-xNd_xOs₄Sb₁₂

The compounds PrOs₄Sb₁₂and NdOs₄Sb₁₂ have attracted interest due to their low temperature properties. They exhibit unconventional heavy-fermion superconductivity and ferromagnetism respectively. The series of compounds Pr_1-xNd_xOs₄Sb₁₂ is being studied to understand the interaction between these effects. Previous studies have shown competition between the superconducting and ferromagnetic states and that for particular concentrations of Nd and Pr, the two coexist within the sample. The specific heat was measured in the normal state above 10 K, and thermodynamic parameters were extracted from the specific heat data for each sample, including the Debye and Einstein Temperatures and the electronic specific heat coefficient. Specific heat and parameter values will be reported for measured samples with low Nd concentrations. A minimum in the Debye and Einstein Temperatures was found around x = 0.55, which suggests a form of lattice-softening taking place at the Nd concentration where the superconductivity disappears.