Quasi-linear 'non-metallic' resistivity in the distorted-kagome metal CrPdAs.

We report the growth and characterisation of single crystals of the distorted-kagome lattice compound CrPdAs. Spin-glass behaviour withis observed in all crystals tested. Some growths show in addition a magnetic impurity phase witharound 200 K, but annealing produces single-phase crystals without the ferromagnetic impurity phase. Single-phase crystals nevertheless haveanti-site disorder of the Cr and Pd sites, similar to a previous generation of flux-grown polycrystalline samples. We observe a large linear-coefficient of the heat capacity at low temperature,mJ mole K, which is typical of kagome metals. The calculated band structure shows several Dirac band-crossings very nearwhose degeneracy is lifted when spin-orbit interaction is included. Our most curious finding is that the in-plane resistivity falls with increasing temperature, i.e. is 'non-metallic', over the entire measured temperature range from 2 K up to 300 K, and that this negative-slope resistivity is quasi-linear inbelow about 130 K, with no sign of saturation down to the lowest temperature measured.