Positive Muon Knight Shift Measurements in U_{0.965}Th_{0.035}Be_{13}   Single Crystals
  Muon spin rotation measurements of the temperature dependence of the Knight shift in single crystals of U_{0.965}Th_{0.035}Be_{13} have been used to study the static spin susceptibility below the transition temperatures T_{c1} and T_{c2}. While an abrupt reduction of the susceptibility with decreasing temperature is observed below T_{c1}, the susceptibility does not change below T_{c2} and remains at a value below the normal-state susceptibility. In the normal state we find an anomalous anisotropic temperature dependence of the transferred hyperfine coupling between the muon spin and the U 5f-electrons. 
J.E. Sonier, R.H. Heffner, D.E. MacLaughlin, G.J. Nieuwenhuys, O.   Bernal, R. Movshovich, P.G. Pagliuso, J. Cooley, J.L. Sm...