Heavy-fermion behavior of the ferrimagnetic compound UCu5Sn

We have measured ac-magnetic susceptibility, magnetization, electrical resi stivity, magnetoresistance, and specific heat on the polycrystalline sample UCu5Sn. The specific heat over temperature shows a strong increase at low temperatures. The electronic specific heat coefficient gamma of 330 mJ/K(2) mol determined by extrapolation to T=0 K classifies this compound as a mode rate heavy-fermion system. The other measurements together with neutron dif fraction reveal that this compound orders ferrimagnetically at T-c=53.5 K. The temperature dependence of the magnetic resistivity of UCu5Sn indicates a behavior consistent with Kondo-type interactions with T-K=15 K in the pre sence of crystalline electric field effects. [S0163-1829(99)06731-4].