Spin-cluster glass state in U(Ga_0.95Mn_0.05)₃

We report the study of a low temperature cluster glass state in 5% Mn-doped UGa₃ heavy fermion compound. This compound transforms from a paramagnetic state to a spin-cluster glass state, which is confirmed by measuring the dc susceptibility and magnetization. The ac susceptibility exhibits a frequency-dependent peak around T_f, which provides direct evidence of the cluster glass state. By analyzing the field-dependent magnetization and frequency-dependent ac susceptibility in detail, we deduce that this compound forms a spin-cluster glass state below T_f.