Local magnetic properties of (RE)12Co5Bi(RE)12Co5Bi studied by μSRμSR

The recently discovered (RE)12Co5Bi(RE)12Co5Bi (where RE is a rare-earth element) system has a rich magnetic phase diagram. In this paper, we report studies on polycrystalline samples of RE=TbRE=Tb, Gd and Tm in order to obtain local magnetic information on the samples. In low fields, the Tb and Gd compounds show a magnetic transition at ≈75≈75 and ≈100K, respectively, while there is no evidence of a magnetic transition down to 3 K in the Tm sample. These results are compared with bulk magnetization measurements. The magnetic ground state in Tm12Co5BiTm12Co5Bi appears to be dramatically different in low compared to high fields, indicative of a meta-magnetic transition.