Partial Magnetic Order in the Anisotropic Triangular Lattice System CeCd₃As₃

CeCd₃As₃ is one member of a family of rare earth ternary compounds which crystallize into a hexagonal ScAl₃C₃-type structure, where the magnetic Ce-ions form a quasi two dimensional anisotropic triangular lattice. Such model geometrically frustrated systems have been proposed as candidates for quantum spin liquid behavior [1].

We report a muon spin relaxation investigation of the low temperature partially ordered phase and associated spin fluctuations of this material. The growth of an anomalous and sizable magnetic contribution to the specific heat below 10 K in CeCd₃As₃ has been found to correspond to enhancement in the spin lattice relaxation rate, which onsets on a temperature scale 20x the ordering transition. Tuning the conductivity through chemical substitution, we discuss the roles of geometric magnetic frustration, Kondo and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in interpreting the response of this Ce based intermetallic compound.

[1] P. Fazekas and P. Anderson, Philos. Mag. 30, 423 (1974)