Single crystal growth of the metallic triangular-lattice antiferromagnet PdCrO2

We report details of single crystal growth of the metallic triangular-lattice antiferromagnet PdCrO2 consisting of layers of Pd triangles and Cr triangles stacking along the c-axis. We used the NaCl flux method and obtained the crystals with the size as large as 2×3.5×0.3 mm3. We confirmed that single crystals have the delafossite structure with the R3¯m symmetry. The electrical resistivity along the c-axis and that in the ab   plane exhibit metallic temperature dependence with the anisotropic ratio ρc/ρabρc/ρab of over 300 at low temperatures. The residual resistivity of as small as ρ0,ab=45nΩcm and the residual resistivity ratio of over 100 indicate high quality of the crystals investigated. Nevertheless, there is no sign of superconductivity down to 0.3 K. These crystals are useful for the investigation of anisotropic magnetic and transport properties including the unconventional anomalous Hall effect (AHE).