Nearly itinerant ferromagnetism in CaNi2 and CaNi3

Single crystals of CaNi2 and CaNi3 were successfully grown out of excess Ca. Both compounds manifest a metallic ground state with enhanced, temperature dependent magnetic susceptibility. The relatively high Stoner factors of Z = 0.79 and Z = 0.87 found for CaNi2 and CaNi3, respectively, reveal their close vicinity to ferromagnetic instabilities. The pronounced field dependence of the magnetic susceptibility of CaNi3 at low temperatures (T < 25 K) suggests strong ferromagnetic fluctuations. A corresponding contribution to the specific heat with a temperature dependence of T^3lnT was also observed.