Low Temperature Specific Heat of Nearly and Weakly Ferromagnetic Y(Co1-xAlx)2

The low temperature specific heat of nearly and weakly ferromagnetic Y(Co 1- x Al x ) 2 with 0≤ x ≤0.18 is studied between 1.4 K and 6.5 K. The results show an enhancement of the electronic specific heat coefficient, γ, around the critical concentration for ferromagnetism. A strong upturn in the C / T vs T 2 curve at low temperatures is observed for x ≥0.09. The origin of this upturn is discussed in terms of different models so far proposed.