Single Crystal Growth and Electronic State of UPd2Cd20

We succeeded in growing single crystals of UPd2Cd20 by the Cd self-flux method. This compound crystallizes in the cubic CeCr2Al20-type structure. From the low-temperature electrical resistivity and Kadowaki-Woods relation, the electronic specific heat coefficient γ is estimated to be about 400mJ/mol ·K2. The magnetic susceptibility of UPd2Cd20 indicates a broad max-imum at 6.6K and a rapid decrease at 5.0K, which correspond to the formation of the heavy fermion state and the antiferromagnetic transition, respectively. These experimental results strongly suggest that UPd2Cd20 is a new heavy fermion antiferromagnet.