Nuclear magnetic resonance in random fields: Cluster formation and local dynamics of a deuteron glass
NMR in statistischen Feldern - Clusterbildung und lokale Dynamik in einem Deuteronenglas
NMR show that the deuteron "pseudo-spin-glass" transition in Rb(1-x)(ND4)xD2PO4(RbDP-ADP) is not just a simple kinetic slowing down process but is characterized by a gradual condensation of randomly polarized clusters as expected if we deal with a percolation transition in eigenstate space. The results provide novel information on the temperature dependence and distribution of local random fields and their dynamics. The spin-lattice and motional-narrowing data further suggest that the "pseudo-spin" O-D-O deuteron intrabond motion determines the freezing dynamics.