Surface segregation of primary glassy nanoparticles of Fe90Sc10 nanoglass

•Majority component segregation is observed in Fe-Sc glassy nanoparticles.•A monolayer model is applied to explain the majority component segregation.•The structure of Fe90Sc10 nanoglass is chemically heterogeneous.•The Fe enriched interfaces of Fe90Sc10 nanoglass are observed directly.

Electron energy loss spectroscopy (EELS) technique has been used to map the elemental distribution in Fe90Sc10 primary glassy nanoparticles (GNp) and in the corresponding nanoglass (NG) produced by consolidation of the GNp. Due to the effect of surface segregation, Fe has been identified to enrich at the surfaces of the primary GNp. This behavior was found to agree with the theoretical results calculated based on a monolayer model. In addition, the heterogeneous structure of Fe90Sc10 NG with Fe enriched interfaces have also been observed directly, which may be attributed to the surface segregation of the primary GNp.