Fe clusters have been dispersed in Ag matrices using cluster beam (CB) sources without any heat treatment. Their structure and morphology have been studied by comparison with those of the sputter-deposited FeAg alloys using small angle X-ray scattering, high resolution transmission electron microscopy and extended X-ray absorption fine structure measurements. In the granular alloys made by CB, bcc Fe clusters of a few nanometers dimension are detected, together with ten-nanometer scale geometrical and chemical fluctuations. In the sputter-deposited alloys, the Fe atoms are rather well mixed with the Ag atoms in the as-deposited state, and fcc Fe clusters are first formed and transform to larger bcc particles with increasing annealing temperature. The field-dependence of the magnetoresistance is well correlated with the growth mode of the Fe clusters in the granular alloys.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry