Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Final Activity Report Summary - NANOMAG-LAB (Combined study of nanostructured magnetic materials)

NANOMAG-LAB project enabled change of research topics of Laboratory of Magnetism from ones connected with classical magnetic films to modern ones related to magnetic nanostructures. For this purpose we adopted our experimental setups and created new ones. Because of NANOMAG-LAB transfer of knowledge underwent both into Bialystok and from Bialystok to collaborating centres in Poland as well as in another European countries.

One of the base topics of Nanomag-Lab project was the problem of producing of nanostructured magnets. In collaboration with laboratories in Orsay, a lot of work has been done concerning the optimisation of the deposition process of both plane and vicinal sample. Both magnetic sputtering and molecular beam epitaxy methods have been used, including in-situ control of grow parameters. Special attention has been paid to the question of the correlation between structural and magnetic properties. In the next step, selected samples have been patterned by means of: electron beam lithography (EBL), focused ion beam (FIB), local laser annealing, ion irradiation through mask. As a result, magnetic objects with limited planar sizes, like nano-dots and nano-wires, have been obtained with magnetic properties different in comparison to the virgin sample. Another important topic was connected with the development of experimental techniques. Giant progress in scanning probe microsopy (SPM) has been done in Bia?ystok.

Using the experience of incoming researchers and additional founds obtained from Polish Government, an unique (in the scale of Poland) SPM equipment has been purchased and started, allowing complex investigation of magnetic properties of nanostructured samples in different circumstances (including e.g. external magnetic fields, vacuum and wide range of temperature). Similarly, a modern laboratory of femtosecond magnetooptic techniques has been built in the University of Bia?ystok, allowing investigation of both non-linear magnetooptic processes and ultrafast magnetisation reversal in metallic, as well as dielectric magnets. Significant progress has been also done in Kerr-effect-based magnetooptical (MOKE) both micro- and mili-magnetometry.

In collaboration with the laboratory in Dresden, magnetooptical microscopic vector analysis of spatial distribution of magnetisation has been learnt and then implemented in University of Bia?ystok, using new generation CCD camera. In mili-magnetometry, computer controlled XY-shift-stage has been arranged as a part of the MOKE set-up, allowing scanning automatised measurement of histeresis loops of patterned samples. An important part of the magnetooptics development has been connected with modelling of the magnetooptical response of a multilayer system. Such modelling has been used to separate signal contribution coming from different layers and - as a consequence - to extract magnetic properties of different layers. Ferromagnetic resonance (FMR) techniques has been also developed in University of Bia?ystok, by means of computer controlling and expanding the experimental possibility to low temperature. Vibrating sample magnetometer VSM was constructed for studies of selected nanostructures. Nanomag-Lab project enabled nanostructures measurements using several special techniques outside of Bia?ystok, such as Brillouin light scattering (BLS) in Kaiserslautern and some large scale facilities such as different options of synchrotron radiation applications and polarised neutron reflectivity (PNR).

The problem of modification of magnetic properties of cobalt layer by both buffer and cover layer, has been successfully solved. Parallel to the experimental works, theoretical approaches have been intensively developed in the aim to describe observed effects properly, especially connected with different ways of tuning of spin reorientation in nanostructures. Scientific results of performed studies were reported in 75 papers, and 139 conference presentations.

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