| Research Abstract |
The Hall coefficient (R_H) and thermoelectric power (S) have been systematically investigated on f-electron compounds down to the He^3 temperature region. The lower temperature measurements using a dilution refrigerator have been also proceeded. Special emphasis were put on the materials exhibiting non-Fermi liquid anomalies which have been the systems of current interest in the field of f-electrons. In order to obtain reliable results, we have started from the high quality crystal growth for each system. For comparison with R_H and S, we also measured the resistivity (P), specific heat, and magnetic susceptibility.
Y_<0.8>U_<0.2>Pd_3 : R_H shows a linear increase with decreasing temperature, which is slight1y strange as an ordinary magnetic systems. It can be understood, however, as due to the anomalous Hall effect, if we take into account the closeness of the concentration to the 0 K-spinglass transition.
CeNi_2Ge_2 : R_H at high temperatures could be explained as due to the ordinary skew scattering, while R_H at low temperatures does not follow the relation, R_H * P^2, predicted from the Fermi liquid (FL) theory. It rather follows R_H * ln(p) in a wide temperature range. At this stage, however, we cannot conclude that the deviation from the FL prediction in R_H is directly related with the non-FL behaviors in the other properties.
Y_<1-x>U_xRu_2Si_2, Th_<1-x>U_xRu_2Si_2 : These systems were the most probable candidates exhibiting anomalies originating from the two channel Kondo effect. Anomalous behaviors appear below a characteristic temperature (T_c). R_H was also found to exhibit an anomalous decrease below T_c, which is hardly explainable within the ordinary anomalous Hall effect. We also found S sharply decreases below T_c and shows a deep minimum at lower temperatures.
CeFe_2Ge_2 : We found CeFe_2Ge_2 to be a new heavy Fermion metamagnet which shows anomalous transport properties, suggesting the non-FL behavior related with the spin fluctuation.
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