Thermal expansion of Al3Ce at very low temperatures

Below 1 K the thermal expansion coefficient α of Al3Ce is negative and linearly approaches zero at 0 K. The pressure variation of the specific heat yT deduced from the initial variation of α is very strong : ∂γ/∂P = 0.62 J/K2 mole kbar . These properties cannot be interpreted with a single ion Kondo effect model but can be interpreted in terms of Fermi liquid (F.L.) behaviour. The magnetostriction experiments clearly show the differences between an ordinary F.L. such as 3He and the F.L. built with a lattice of magnetic ions coupled with and by itinerant electrons.