Anomalous f-electron Hall effect in the heavy-fermion system CeTIn5 (T=Co, Ir, or Rh) -: art. no. 035113

The in-plane Hall coefficient R-H(T) of CeRhIn5, CeIrIn5, and CeCoIn5, and their respective nonmagnetic lanthanum analogs are reported in fields up to 90 kOe and at temperatures from 2-325 K. R-H(T) is negative, field independent, and dominated by skew scattering above similar to50 K in the Ce compounds. R-H(H-->0) becomes increasingly negative below 50 K and varies with temperature in a manner that is inconsistent with skew scattering. Field-dependent measurements show that the low-T anomaly is strongly suppressed when the applied field is increased to 90 kOe. Measurements on LaRhIn5, LaIrIn5, and LaCoIn5 indicate that the same anomalous temperature dependence is present in the Hall coefficient of these nonmagnetic analogs, albeit with a reduced amplitude and no field dependence. Hall angle (theta(H)) measurements find that the ratio rho(xx)/rho(xy)=cot(theta(H)) varies as T-2 below 20 K for all three Ce-115 compounds. The Hall angles of the La-115 compounds follow this T dependence as well. These data suggest that the electronic-structure contribution dominates the Hall effect in the 115 compounds, with f electron and Kondo interactions acting to magnify the influence of the underlying complex band structure. This is in stark contrast to the situation in most 4f and 5f heavy-fermion compounds where the normal carrier contribution to the Hall effect provides only a small, T-independent background to R-H.