uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Influence of interface mixing on the magnetic properties of BCC Fe0.82Ni0.18/V (001) superlattices
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics.
Show others and affiliations
2003 In: Journal of Magnetism and Magnetic Materials, Vol. 267, 234-243 p.Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2003. Vol. 267, 234-243 p.
URN: urn:nbn:se:uu:diva-91260OAI: oai:DiVA.org:uu-91260DiVA: diva2:163929
Available from: 2004-01-19 Created: 2004-01-19 Last updated: 2013-03-21
In thesis
1. Growth and Magnetic Properties of Fe- and FeNi-based Thin Films and Multilayers
Open this publication in new window or tab >>Growth and Magnetic Properties of Fe- and FeNi-based Thin Films and Multilayers
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis concerns the growth and magnetic properties of thin films and multilayers. The samples were grown by magnetron sputtering, and characterized structurally mainly by x-ray diffraction and reflectivity. The magnetic characterization of the multilayers was done by magneto-optical Kerr technique, SQUID magnetometry and, in two samples, by neutron reflectometry.

Arrays of small elements of polycrystalline permalloy (FeNi alloy with 19 wt% Fe) are of interest as a component in non-volatile magnetic random access memories (MRAM). Here the shape dependence of the domain structure in such elements was studied by magnetic force microscopy (MFM) and in thin ring magnets the 'onion' state could be seen for the first time. Also, by post-annealing in hydrogen atmosphere the number of domains decreased in each element due to enhanced relaxation and defect reduction.

Furthermore, permalloy-based anisotropic magnetoresistance (AMR) in read heads are nowadays replaced by material combinations that have a giant magnetoresistance (GMR) effect. In this work Fe/V(001) and Fe0.82Ni0.18/V(001) superlattices, i.e. single-crystal-like multilayers, were investigated. These systems showed much smaller GMR effect compared to the Fe/Cr system. However, by introducing Ni into the Fe layers the magnetic anisotropy and the interlayer exchange coupling (IEC) decreased, thereby increasing the sensitivity, which is a key property for a magnetic sensor. The interface region showed a reduced magnetic moment, and the influence of the structural quality was modelled and investigated theoretically in the Fe0.82Ni0.18/V case. Also, in the Fe(2-3 ML)/V(x ML) superlattices (ML=monolayers) the transition temperature from long-range magnetic order to paramagnetic order oscillated with the V layer thickness (x) as a result of the oscillatory behaviour of the IEC.

The introduction of hydrogen in the non-magnetic layers of, for example, Fe/V(001) superlattices is a way to tune the IEC strength. Here the tuning was used as a tool to study the magnetic order in a low-dimensional magnet. At the critical hydrogen concentration <H/V>=0.022 the Fe layers in an Fe(2 ML)/V(13 ML) superlattice became decoupled. Then the system behaved as a two-dimensional Ising magnet with a finite ordering temperature of about 60 K.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2004. 62 p.
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 927
Physics, Sputter growth, Permalloy, Multilayer, Superlattice, Magnetism, Fysik
National Category
Physical Sciences
urn:nbn:se:uu:diva-3940 (URN)91-554-5849-1 (ISBN)
Public defence
2004-02-13, Polhemssalen, Ångström laboratoriet, Lägerhyddsvägen 1, Polacksbacken, Uppsala, 10:15
Available from: 2004-01-19 Created: 2004-01-19Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Nordblad, Per
By organisation
Department of Physics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 193 hits
ReferencesLink to record
Permanent link

Direct link