Effects of low Pr substitution on the T-H phase Diagram of Ce_1-xPr_xOs₄Sb₁₂ (x ≤ 0.25)

The filled skutterudite CeOs₄Sb₁₂ is a heavy-fermion compensated semimetal that exhibits a spin-density-wave type antiferromagnetic phase below ~1 K. Theoretical predictions suggest that it may host a topologically protected state with coexisting electron and hole Fermi surfaces at low temperatures. Previous studies have revealed a near-spherical Fermi surface above 28 T, an enhancement of cyclotron mass below 35 T, and a valence transition characterized by a distinctive reverse wedge-shaped temperature (T) - magnetic field (H) phase diagram [1,2]. Substituting Pr for Ce is expected to introduce additional hole carriers. In this work, we extend the Pr substitution study [3] in Ce_1-xPr_xOs₄Sb₁₂ for x=0.15 and 0.25 to investigate the resulting electronic properties and the evolution of T-H phase diagram.

REF [1] K. Götze et. al, New J. Phys. 24, 043044 (2022); PRB 101, 075102 (2020). [2] P.-C. Ho et. al, PRB 94, 205140 (2016). [3] L. M. Ramos et. al, APS March Meeting, Abstract # A30.00006 (2023).