LOW-TEMPERATURE SPECIFIC-HEAT OF UNISI2

Recently discovered new uranium compound UNiSi2 has been investigated by means of specific heat, magnetization and susceptibility measuremen ts. UNiSi2 orders ferromagnetically at T-c = 95 K and the experimental effective magnetic moment mu(eff) = 1.9 mu(B) is apparently much smal ler than the value expected for the free U4+ or U3+ ions (3.58 mu(B) a nd 3.64 mu(B), respectively). This large reduction of the effective ma gnetic moment presumably arises due to the Kondo effect. The magnon co ntribution to the specific heat has not been observed and the electron ic specific heat coefficient gamma = 27 mJ/mol K-2 suggests that UNiSi 2 is not a heavy fermion system. (C) 1998 Elsevier Science B.V. All ri ghts reserved.