Local moment ferromagnetism in CeRu ₂Ga ₂B

Magnetization, specific heat, and electrical resistivity measurements for polycrystalline specimens of CeRu ₂Ga ₂B reveal local moment ferromagnetic order at a Curie temperature T _C=16.3K. Specific heat measurements show that the phase transition is second order and the low temperature behavior indicates that the Ce f-electron states do not hybridize strongly with the conduction electron states. Electrical resistivity measurements demonstrate large spin disorder scattering of conduction electrons for TT _C. Results for a single crystal are also reported, where T _C=15.4K. While results for the polycrystal and single crystal specimens are qualitatively similar, the differences between them suggest that crystalline disorder plays a role in how the magnetism develops.