High-pressure synthesis and characterizations of a new ternary Ce-based compound Ce₃TiAs₅

We report the structure and properties of a new Ce-based compound Ce₃TiAs₅synthesized under high-pressure and high-temperature conditions. It crystallizes in a hexagonal Hf₅Sn₃Cu-anti type structure with zig-zag like Ce chains along thecaxis. This compound is metallic and undergoes a magnetic phase transition atT_N= 13 K. A metamagnetic transition occurs at ∼0.7 T. The Sommerfeld coefficient for the compound is determined to be about 215 mJ/(Ce-mol*K²), demonstrating a heavy Fermion behavior. The resistivity is featured with two humps, which arises from the synergistic effect of crystal electric field and magnetic scattering. The magnetic ordering temperatureT_Ngradually increases in the sequence of Ce₃TiPn₅with Pn = Bi, Sb, and As, which implies that the Ruderman-Kittel-Kasuya-Yosida interaction should be still predominant in Ce₃TiAs₅.