Divergence of the Gruneisen Parameter and Magnetocaloric Effect at Heavy Fermion Quantum Critical Points

At any pressure sensitive quantum critical point (QCP) the thermal expansion is more singular than the specific heat leading to a divergence of the Gruneisen parameter. For a magnetic field sensitive QCP, the complementary property is the magnetic Gruneisen ratio which equals the magnetocaloric effect. Here we use both properties to investigate magnetic QCPs in different heavy fermion (HF) metals starting from CeNi2Ge2. The influence of dimensionality on quantum criticality is addressed by the comparison of cubic CeIn3-x Sn (x) with layered CeMIn5-x Sn (x) (M = Co, Rh) systems, in which Sn doping both acts as tuning parameter and introduces slight disorder. Near the field-tuned QCP in undoped CeCoIn5 a crossover scale T (a T (a