Title
The role of Fe-doping on structural and magnetic properties of Fe nanoclusters in thick Yb films
Date Issued
01 November 2016
Access level
open access
Resource Type
journal article
Author(s)
Passamani E.
Sousa M.
Litterst F.
Baggio-Saitovitch E.
Publisher(s)
Elsevier B.V.
Abstract
Structural and magnetic properties of co-deposited (x at.% Fe)Yb (0.3≤x≤5.0) films have systematically been investigated by X-ray absorption spectroscopy, 57Fe Mössbauer spectroscopy, magnetization measurements, and Ferromagnetic Resonance (FMR) experiments. Mössbauer and magnetization data indicate formation of two types of Fe clusters that are supposed to be at grain boundaries in fcc- and hcp-like Yb structures. Clusters stay superparamagnetic down to 3 K for low Fe concentrations x. For the highest studied Fe concentration x=5.0 we find blocking behavior typical for only very weakly interacting cluster magnetic moments with blocking temperature of ca. 7 K. EXAFS can only resolve one type of Fe-Fe and one of Fe-Yb nearest neighbor coordination, both with a lack of long-range structural order. While the coordination number of Fe increases and that of Yb decreases with increasing Fe concentration (as expected for a growing size of Fe clusters), the nearest neighbor distances remain practically unchanged for different Fe content. Estimated cluster sizes are on the order of nm. FMR experiments suggest that the average ratio of orbital to spin magnetic moment of Fe in (x at.% Fe)Yb films decreases with increasing x thus indicating the decreasing contribution from the fraction of Fe atoms on the cluster surfaces.
Start page
175
End page
181
Volume
417
Language
English
OCDE Knowledge area
Nano-materiales Física de la materia condensada
Scopus EID
2-s2.0-84974603832
Source
Journal of Magnetism and Magnetic Materials
ISSN of the container
03048853
Sponsor(s)
This work has been made possible by financial support from FAPERJ (Bolsa Nota 10 E-26/100.382/2012 ), CAPES, FAPES, Brazilian-German research program PROBRAL (CAPES-DAAD) .
Sources of information: Directorio de Producción Científica Scopus