Semimetallic Kondo lattice behavior in YbPdAs with a distorted kagome structure

W. Xie, F. Du, X. Y. Zheng, H. Su, Z. Y. Nie, B. Q. Liu, Y. H. Xia, T. Shang, C. Cao, M. Smidman, T. Takabatake, H. Q. Yuan
2022 Physical review B  
We have synthesized YbPdAs with the hexagonal ZrNiAl-type structure, in which the Yb-atoms form a distorted kagome sublattice in the hexagonal basal plane. Magnetic, transport, and thermodynamic measurements indicate that YbPdAs is a low-carrier Kondo lattice compound with an antiferromagnetic transition at T_N = 6.6 K, which is slightly suppressed in applied magnetic fields up to 9 T. The magnetic entropy at T_N recovers only 33% of Rln2, the full entropy of the ground state doublet of the
more » ... ons. The resistivity displays a -ln T dependence between 30 and 15 K, followed by a broad maximum at T_coh = 12 K upon cooling. Below T_coh, the magnetoresistance changes from negative to positive, suggesting a crossover from single-ion Kondo scattering processes at intermediate temperatures to coherent Kondo lattice behaviors at low temperatures. Both the Hall resistivity measurements and band structure calculations indicate a relatively low carrier concentration in YbPdAs. Our results suggest that YbPdAs could provide an opportunity for examining the interplay of Kondo physics and magnetic frustration in low carrier systems.
doi:10.1103/physrevb.106.075132 fatcat:em26tokly5d53kknuiebdknrby