Low-temperature dynamics of local-moment systems investigated by thermal cycling methods

We report studies of the low-temperature dynamics of several dilute alloy systems in which local moments are present, using various thermal-cycling nuclear orientation methods. Determinations of nuclear spin-lattice relaxation over a wide concentration range in the giant-moment alloys CoPd illustrate the various types of magnetic behavior in this system. Experiments on dilute TbAu show evidence of clustering and impurity-impurity interactions. Strong local moments are formed on Mn in the weak ferromagnet ZrZn₂, but the relaxation behaves as in a paramagnetic alloy.