title: Diffusion in a metallic melt at the critical temperature of mode coupling theory.
abstract: According to mode coupling theory, liquidlike motion becomes frozen at a critical temperature T(c) well above the caloric glass transition temperature T(g). Here, for the first time, we report on radiotracer diffusion in a supercooled Pd43Cu27Ni10P20 alloy from T(g) to the equilibrium melt. Liquidlike motion is seen to set in exactly above T(c) as evidenced by a gradual drop of the effective activation energy. This strongly supports the mode coupling scenario. Isotope effect measurements, which have never been carried out near T(c) in any material, show atomic transport up to the equilibrium melt to be far away from the hydrodynamic regime of uncorrelated binary collisions.
authors.affiliation: Lehrstuhl für Materialverbunde, Technische Fakultät der Universität Kiel, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Zöllmer
authors.forename: Klaus
authors.initials: K
authors.lastname: Rätzke
authors.forename: Franz
authors.initials: F
authors.lastname: Faupel
authors.forename: Andreas
authors.initials: A
authors.lastname: Meyer