Thermal Analysis of Pr_1-xNd_xOs₄Sb₁₂in Normal State

At low temperatures, the filled-skutterudite compounds PrOs₄Sb₁₂ and NdOs₄Sb₁₂ exhibit states of unconventional heavy-fermion superconductivity (SC) and ferromagnetism (FM), respectively. Thus, we have interest in studying the doping system of Pr_1-xNd_xOs₄Sb₁₂ in order to identify the competing mechanisms between the two states. Because the multiband superconductivity in this system may still be influenced by the electron-phonon mechanism, the normal state properties may give us insight into the properties of conduction electrons and phonons. The molar specific heat of Pr_1-xNd_xOs₄Sb₁₂ is measured in the normal state 10K-300K, and the thermodynamic parameters are extracted by incorporating Debye Temperature, Einstein Temperature, and the electronic specific heat coefficient, which provide information about the lattice stiffness, rattling effect, and electron correlation, respectively. Our findings convey that the Debye and Einstein temperatures have a V shaped x dependence that decreases towards central values of x, following the trend in transition temperature of low temperature ordered state.