THE GIANT MUON KNIGHT-SHIFT IN ANTIMONY - EVIDENCE FOR A KONDO IMPURITY

A detailed study has been undertaken of the muon Knight shift in high purity antimony single crystals. No periodic variations with magnetic field (de Haas-van Alphen oscillations) are observed. The temperature dependence below 175 K is close to that expected for a Kondo-like impu rity with an anisotropic muon-electron hyperfine interaction. At highe r temperatures the paramagnetic state becomes unstable and a transitio n occurs to a second state. The longitudinal relaxation rate rises fro m an apparently non-zero value at T = 0 to a maximum at 50 K, followed by a slow decline. This leads to a Korringa product which is strongly temperature dependent.