Giant Magnetoresistance in Electrochemical Deposited CoFe/Cu Multilayers Depending on Fe Concentration

Abstract

Electrochemical deposition of CoFe/Cu multilayers were performed on Ti substrate from a single bath. 0.025, 0.05 and 0.1 M Fe concentration were used in electrolytes. The deposition potentials were selected − 1.5 V for magnetic layers and − 0.3 V for non-magnetic layers with respect to saturated calomel electrode. The current-time transients were obtained during the deposition process. The X-ray diffraction was used to define the structure of the multilayers. The multilayers were found to be face-centred cubic structure such as bulk Cu. Their lattice parameter and inter-planar distances values confirm this result. The magnetic measurements were performed at room temperature under 2 kOe external magnetic field. The results show that the saturation magnetization gradually increased from 27 to 50 emu/cm3 with increasing 0.025 to 0.05 M Fe concentration in electrolyte, and in the multilayer prepared from the electrolyte containing 0.1 M Fe concentration, this value drastically decreased to 18 emu/cm3. The magnetoresistance measurements were carried out in magnetic fields in the range of ± 1.2 kOe. The high GMR value (18 %) and sensitivity (4.4 %/Oe) were obtained for this multilayer.