Resistivity of Doped Filled Skutterudite Compounds: Ce$_{1-x}$Pr$_x$ Os$_4$Sb$_{12}$

Filled skutterudite compounds are described by the chemical formula: LnT$_{4}$Pn$_{12}$ where Ln is a rare-earth metal, T is a transition metal, and Pn is a pnictogen. CeOs$_{4}$Sb$_{12}$ is a Kondo insulator that exhibits antiferromagnetism due to spin-density wave formation below 1 K. Based on the band-structure calculation, CeOs$_{4}$Sb$_{12}$ is suggested to be a candidate for topological insulators [1], which may have a hole Fermi surface and an electron Fermi surface coexisting at low temperatures. Through our previous study of CeOs$_{4}$Sb$_{12}$ [2,3], we found that the valence transition may occur in this compound, and we have established an intriguing temperature, $T$-, magnetic field, $H$, phase diagram in its normal state. Nevertheless, the neighboring isostructural compound PrOs$_{4}$Sb$_{12}$ is a heavy-fermion superconductor with a transition temperature at 1.85 K. When Pr substitutes Ce in CeOs$_{4}$Sb$_{12}$, a hole-doping is introduced. We plan to study the series of Ce$_{1-x}$Pr$_x$ Os$_4$Sb$_{12}$ to investigate the influence of hole-doping to the valence transition. In this report, we will show the preliminary results of normal state resistivity of two concentrations: x$=$0.1 and x$=$0.2 from 300 K to 12 K at zero magnetic field. [1] B. Yan, et al., PRB 85, 165125 (2012). [2] K. Gotze, et al., PRB 101, 075102 \quad (2020). [3] P.-C. Ho, et al., PRB 94, 205140 (2016).