UC Irvine

We have used resistance measurements at pressures to 95 kbar and magnetic fields to 8 T to probe the establishment of Kondo coherence in the heavy-fermion Kondo lattice UBe13. With increasing pressure, the negative magnetoresistance characteristic of noninteracting Kondo impurities evolves into the positive magnetoresistance expected for a coherent Kondo lattice. We show that coherence is established by the suppression of inelastic scattering, over a temperature range which expands as pressure decreases the superconducting transition temperature Tc and increases the Kondo temperature Tk. © 1989 The American Physical Society.