Positive Muon Knight Shift Measurements in U_{0.965}Th_{0.035}Be_{13} Single Crystals
J.E. Sonier, R.H. Heffner, D.E. MacLaughlin, G.J. Nieuwenhuys, O. Bernal, R. Movshovich, P.G. Pagliuso, J. Cooley, J.L. Smith, J.D. Thompson
Abstract
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.