Magnetism and Specific Heat of TmRhX (X = Ga, Ge) Compounds

Magnetic and specific heat data of the TmRhX (X = Ga, Ge) compounds are reported. These compounds crystallize in an orthorhombic crystal structure of the TiNiSi-type (space group Pnma). Magnetic data indicate that the compounds are antiferromagnets with the Néel temperature $T_{N}$ equal to 3.9 K for TmRhGa and 6.0 K for TmRhGe. Magnetic susceptibility of TmRhGe has an additional peak at $T_{t}$ = 10.6 K. In TmRhGe temperature dependence of χ"(T), the positions of both the peaks at $T_{N}$ and $T_{t}$ change with frequency indicating a relaxation process. These data suggest that with the decreasing temperature, first a cluster glass state and next the long-range aniferromagnetic order exists.