Realization of Kondo chain in CeCo2Ga8

We revisited the anisotropy of the heavy-fermion material CeCo2Ga8 by measuring the electrical resistivity and magnetic susceptibility along all the principal a, b, and c axes. Resistivity along the c axis (rho(c)) shows clear Kondo coherence below about 17 K, while both rho(a) and rho(b) remain incoherent down to 2 K. The magnetic anisotropy is well understood within the theoretical frame of crystalline electric field effect in combination with magnetic exchange interactions. We found the anisotropy ratio of these magnetic exchange interactions vertical bar J(ex)(c)/J(ex)(a,b)vertical bar reaches a large value of 4-5. We, therefore, firmly demonstrate that CeCo2Ga8 is a quasi-one-dimensional heavy-fermion compound both electrically and magnetically, and thus provide a realistic example of Kondo chain.