A brief review is given on positron annihilation (PA) results focusing on e+‐trapping in metallic glassy alloys of various compositions. The influence of production parameters on the amount and distribution of the frozen‐in “free volume” is pointed out. For several compositions a comparison of PA‐data with results obtained by other experimental techniques (Mössbauer‐effect, resistivity and density measurements, etc.) is given. Structural changes induced by heat treatment, recrystallization, mechanical stress, neutron and electron irradiation are also considered. Different structural models of amorphous alloys (dense random packing, microcrystalline‐, quasi‐crystalline‐model, etc.) are briefly discussed from the point of view of PA. Microcrystallites as fine‐grained alloys represent a class of solids of high practical importance. Due to the large specific surface fraction positron and positronium bound states – not existent in “homogeneous” bulk samples – are formed. The correlation between PA‐parameters and surface properties of micro‐ and nanocrystallites is pointed out.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics