UC Irvine

We report the first Hall effect measurements on polycrystalline thin films of the heavy fermion superconductor UBe13. Measurements have been extended to temperatures well below previous studies on single crystals. We find no sign change of the Hall coefficient when cooling through Tc in contrast to the earlier study. We also observe a "shorting" of the Hall voltage below Tc. As the field is swept up, a p-type Hall signal is observed above a threshold magnetic-field which we define as Hc2. The slope of the phase boundary defined by these values agrees well with that as defined by resistivity measurements. Below T = 0.2 K, the magnetoresistance and Hall signal have very little temperature or field dependence above Hc2. The resistivity as a function of field may be fit using a spin- 1 2 Coqblin-Schreiffer model. © 1989.