tailieunhanh - Electrodeposition of the ultrathin magnetic film NiFe onto acrylon nitril butadiene (ABS) insulating substrate

In this paper, we present results of electrochemical studies on electrodeposition process and magnetic properties of FeNi layers formed on insulating substrates using CoS( ) activation. | Journal of Chemistry Vol. 44 1 P. 96 - 99 2006 ELECTRODEPOSITION OF THE ULTRATHIN MAGNETIC FILM NiFe ONTO ACRYLON NITRIL BUTADIENE ABS INSULATING SUBSTRATE Received 15 December 2004 MAI THANH TUNG1 NGUYEN HOANG NGHI2 1Dep. of Electrochemistry and Corrosion Protection HUT 2Lab. of Amorphous and Nanocrystalline Materials HUT SUMMARY Electrodeposition of magnetic alloy NiFe onto insulating Acrylon Nitril Butadiene ABS substrates by the direct galvanic metallization was studied. Electrochemical behaviour magnetic properties and Giant Magnetoimpedance GMI effect of the obtained alloy were investigated using Cyclic Voltametric CV potentiostatic magnetic hyteresis and GMI ratio measurements. Results show that the electrodeposition of the FeNi alloy takes place in parallel to the reduction of the CoS ft layer. The composition of the alloy was dependent on the deposition potential. The magnetic coercivity achieved 7 Oe and the maximum GMI ratio was 38 . I - INTRODUCTION Electrodeposition of the magnetic bi- or ternary-alloys of iron groups has long been applied for fabricating of magnetic sensors particularly the read-write devices in personal computers. Recently the FeNi alloy with low magnetic coercivity and high resistivity was used as the first layer for magnetic sensors using GMI and GMR effects 1 - 3 . The major problem of the electrodeposition technology for the fabrication of GMI and GMR sensors are that the substrates for those applications must be insulators or semiconductors. Until now metal deposition on insulating or semiconducting surfaces in microsystems can only be carried out by physical vapour deposition PVD or chemical metal deposition. Recently a new method using a locale electrical contact for direct electrodeposition of metals onto modified insulating surfaces direct galvanic metallization has been proposed 4 - 9 . The key step in the direct metallization methods is the activation of the surfaces by conductive 96 CoS P film which has thickness of 10-30