Transport properties of topological nodal-line semimetal candidate CaAs₃ under hydrostatic pressure

We report the transport properties of the CaAs₃ single crystal, which has been predicted to be a candidate for topological nodal-line semimetals. At ambient pressure, CaAs₃ exhibits semiconducting behavior with a small gap, while in some crystals containing tiny defects or impurities, a large “hump” in the resistivity is observed around 230 K. By applying hydrostatic pressure, the samples appear to a tendency towards metallic behavior, but not fully metallized up to 2 GPa. Further high pressure studies are needed to explore the topological characteristics for CaAs₃.