Conference paper · Journal article
Amorphous Fe-B alloys in B-Fe-Ag multilayers studied by magnetization and Mössbauer measurements
Bulk and local magnetic properties were studied in [1 nm B + 1 nm 57Fe + x nm Ag]5, x = 1, 2, 4, 5 and 10, multilayer samples. Although Ag does not mix with either of the other two elements the magnetic properties of the multilayers are strongly influenced by the Ag thickness below x = 5, whereas no such effect is observed above this value.
The Mössbauer measurements indicate a complete amorphization of the thin Fe layers in each sample, as a result of intermixing with the B layers. The variation of the magnetic properties is explained by the variation of the average B concentration of the amorphous Fe–B layers, which depends on the thickness of the Ag barrier layers.
The magnetization measurements indicate ferromagnetic behaviour of the ultra-thin amorphous layers with the presence of less than 10% superparamagnetic moments for x = 5 and 10. The average B concentration of the amorphous Fe–B alloy, as estimated from the Fe hyperfine fields, is around 40 at%. It is significantly lower than the 60 at% nominal B concentration, suggesting the presence of an unalloyed B layer, as well.
This picture is supported by transmission electron microscopy investigations which reveal two amorphous layers of different B concentration in between the crystalline Ag layers.
Language: | English |
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Year: | 2011 |
Pages: | 188-192 |
Proceedings: | 17th International Symposium on Metastable, Amorphous and Nanostructured Materials |
ISSN: | 18734669 and 09258388 |
Types: | Conference paper and Journal article |
DOI: | 10.1016/j.jallcom.2010.11.014 |