Studies of non-fermi liquid behavior in heavy fermion compounds by specific heat measurements under high pressure and magnetic field

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To investigate the non-fermi liquid behavior in Ce heavy fermion systems, electrical resistivity and specific heat of Ce_xL.a_<1-x>Pd_2Al_3 (x = 0〜1.0) with hexagonal structure were measured down to 0.4K. Specific heat was also measured in magnetic fields up to 5T between 0.5 and 4.2K. The main results of this work are ;1. Magnetic specific heat divided by temperature, C_m/T, shows a non-fermi liquid behavior ( -InTdependence) in the wide Ce concentration range below x = 0.7, at which the antiferro-magnetic transition disappears.2. For x ≦ 0.15, the logarithmic divergence in C_m/T is suppressed by application of the magnetic fields indicating a recovery of the fermi-liquid states. Magnetic entropy calculated by integrating C_m/T with T is not enhanced in magnetic fields suggesting that the non-fermi liquid behavior could not arise from 2-channel Kondo effect.3. C_m/T exhibit surprisingly identical temperature dependence in the wide Ce concentration range between x = 0.3 and 0.7. Such concentration dependence characteristic of Ce_xLa_<1-x>Pd_2Al_3 has not been found in other systems.