Thermoelectric properties of Ce(Ni, Pd)2Ge2 at low temperatures below 1K

Thermoelectric power S of single crystals for a nonmagnetic heavy fermion compound CeNi2Ge2 and for the alloys of Ce(Ni1-xPdx)(2)Ge-2 was investigated well below 1K. SIT, S divided by temperature T, logarithmically increases with lowering temperature below 10 K, approaching a large magnitude of about 10 mu V/K-2 in the lowest temperatures along the c-axis of a tetragonal crystal structure for the sample with x = 0.06. This behavior strikingly coincides with the temperature dependence of C/T which leads to a large Sommerfeld coefficient gamma of 630 mJ/K-2 Mol in the zero-temperature limit. On the other hand, S/T for CeNi2Ge2 shows a complex temperature dependence at low temperatures in both axes, and is different from its C/T behavior. These results are regarded as the consequence originating from a non-Fermi-liquid nature evolved at low temperatures in the vicinity of the antiferromagnetic quantum critical point. (c) 2006 Elsevier B.V. All rights reserved.