STRUCTURE OF METALLIC GLASSES - EXPERIMENTS AND MODELS

The topological and the chemical short range order in metallic glasses is discussed by means of representative examples from the systems Ni- P, Ni-B, Nb-Ni, and Dy-Ni. The characterization of the chemical short range order, e.g. in terms of a short range order parameter, depends o n the definition of an appropriate hypothetic statistical reference sy stem. The consideration of the size effect is essential. Some structur al features of metallic glasses point to relationships with the relate d individual crystalline phases, whereas other features show that the different types of metallic glasses have certain construction principl es in common. Small angle scattering with hydrogenated metallic glasse s suggests the presence of extended two-dimensional structures. Revers e Monte Carlo models reveal rather broad distributions of the local st ructural properties and show that metallic glasses are not built as as semblies of defined structural units.