LOW-TEMPERATURE PROPERTIES OF CE(RU0.85RH0.15)(2)SI-2 SINGLE-CRYSTALS

Specific-heat measurements have been performed on single-crystalline s amples of Ce(Ru0.85Rh0.15)(2)Si-2 in various magnetic fields along the tetragonal c-axis up to 8 T in the temperature range between 0.1 and 1.2 K. Ce(Ru0.85Rh0.15)(2)Si-2 shows a weak antiferromagnetic ordering (T-N = 5.5 K) with an incommensurate spin structure. Two transitions (B-C similar or equal to 3.5 T, B-M similar or equal to 5 T) were obse rved in the magnetization process below T-N. The electronic specific h eat coefficient, gamma, increases drastically above B-C, and shows a s ubtle enhancement, then decreases gradually above B-M. This suggests t hat a heavy-electron state is restored by magnetic fields, and further undergoes a metamagnetic transition similar to that of CeRu2Si2 at st ill higher fields.