5th INTERNATIONAL WORKSHOP ON ELECTRODEPOSITED NANOSTRUCTURES 7-9 June 2007, Iasi, Romania	ABSTRACTS

Spin engineering in nanostructured magnetic materials prepared by magnetic electrodeposition Violeta Georgescu Faculty of Physics, "Alexandru Ioan Cuza" University, Carol I Blvd No. 11, Iasi 700506, Romania E-mail: violeta.georgescu@uaic.ro The electrochemical preparation of magnetic nanostructured alloys is often used in the creation of new nanostructured materials that require specific functional properties. There is a considerable interest in controlling magnetic properties of such materials in a view to develop a low-cost method for tailoring the magnetic anisotropy (spin engineering) of nanostructured materials, in order to apply them in the fabrication of micro- and nano-devices. When a magnetic field is externally imposed on an electrochemical cell, an electromagnetic force is induced to move the ions and thus promotes a mass-transport process that influences the film growth. The applied magnetic field influences both the ion transport in the electrolyte and the electron transfer kinetics at the electrode/solution interface. By such a way, the deposit morphology is changed and an induced magnetic anisotropy appears in the magnetic films prepared by this procedure. The present investigation was undertaken to determine the effect of the direction (referring to the cathode plane) of the magnetic field applied during electrodeposition, on the magnetic properties and the morphology of Co-Ni-P plane thin films. We have studied the changes induced by magnetic field in the microstructure and magnetic properties of thin cylindrical Ni and Co-Ni-Mg-N films. The following types of cylindrical multilayers and spin-valves have been studied also in our laboratory and exemplified in the present work: films with spatially varying magnetic anisotropy prepared by magneto electrolysis, multilayers comprising ferromagnetic layers of different coercivities (Ni/Co-Ni-Mg-N). It has been shown that the morphology and magnetic properties (susceptibility and anisotropy) change because of magnetic electrodeposition under applied magnetic field parallel/perpendicular to the cathode surface, in comparison with no-field electrodeposition. The changes in the shape of magnetic susceptibility curves reflect the changes in magnetization processes and in the switching properties of films produced in the presence of a magnetic field during the electrodeposition. Magnetic characteristics, the crystallographic structure and the morphology of electrodeposited films were found to depend on the direction of the applied magnetic field (in the same working conditions). The ability to align the easy axis in a magnetic alloy by magnetic field imposed in electrodeposition provides a practical means of constructing magnetic media with dual directions of magnetization. In this new type of magnetic medium, the spin configurations are engineered in chemically homogenous magnetic films prepared by electrodeposition in the presence of a suitable magnetic field.

 
 
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