Investigation of carrier density in Ce_1-xPr_xOs₄Sb₁₂ (x = 0.1, 0.2)

The filled skutterudite CeOs₄Sb₁₂ is a heavy-fermion compensated semimetal that exhibits a spin-density-wave type antiferromagnetic phase below ~1 K. Theoretical predictions suggested that it may possess a topologically protected state where electron and hole Fermi surfaces coexist at low temperatures. Through previous studies of this compound have revealed a near spherical Fermi surface above 28 T, an enhancement of cyclotron mass below 35 T, and a valence transition with a striking reverse wedge-shape temperature (T) versus magnetic field (H) phase diagram [1,2,3]. Substituting the rare-earth element Pr for Ce introduces hole-doping, while applying pressure acts like electron-doping in CeOs₄Sb₁₂. In this report, we present the effects of Pr substitution on the electronic properties, evolution of T-H phase boundaries of the valence transition, and carrier density in Ce_1-xPr_xOs₄Sb₁₂ (x = 0.1 and 0.2) before superconductivity emerges.

Refs: [1] K. Götze et. al, New J. Phys. 24, 043044 (2022). [2] K. Götze et. al, PRB 101, 075102 (2020). [3] P.-C. Ho et. al, PRB 94, 205140 (2016).