J Supercond Nov Magn (2013) 26:813–817 DOI 10.1007/s10948-012-1912-7 ORIGINAL PAPER Properties of Electrodeposited CoFeNi/Cu Superlattices: The Effect of CoFeNi and Cu Layers Thicknesses Sonser Kalsen · Mursel Alper · Hakan Kockar · Murside Haciismailoglu · Oznur Karaagac · Hilal Kuru Received: 6 November 2012 / Accepted: 30 November 2012 / Published online: 30 December 2012 © Springer Science+Business Media New York 2012 Abstract CoFeNi/Cu superlattices were grown on Ti sub- strate by electrodeposition as a function of the ferromag- netic and non-magnetic layer thicknesses. In order to exam- ine the effect of the Cu layer thickness on the film proper- ties, the Cu layer thickness was changed from 0.5 to 6 nm, while the CoFeNi layer thickness was kept constant at 4 nm. Also, for the CoFeNi layer effect, the CoFeNi layer thick- ness was changed from 2 to 15 nm, while the Cu layer thickness was fixed at 4 nm. The structural analysis stud- ied by X-ray diffraction indicated that the superlattices have face-centered-cubic structure. Magnetic characteristics were investigated by vibrating sample magnetometer. From the hysteresis curves, the coercivity and the saturation magne- tization were determined. It was found that the easy-axis of the films is parallel to the film plane. Magnetoresistance measurements were made by the Van der Pauw method at the room temperature with magnetic fields up to ±12 kOe. S. Kalsen · M. Alper ( ) · M. Haciismailoglu Fen Edebiyat Fakultesi, Fizik Bolumu, Uludag Universitesi, 16059, Gorukle, Bursa, Turkey e-mail: malper@uludag.edu.tr S. Kalsen e-mail: sonser@kalsen.com.tr M. Haciismailoglu e-mail: msafak@uludag.edu.tr H. Kockar · O. Karaagac · H. Kuru Fen Edebiyat Fakultesi, Fizik Bolumu, Balikesir Universitesi, 10145, Cagıs Yerleskesi, Balikesir, Turkey H. Kockar e-mail: hkockar@balikesir.edu.tr O. Karaagac e-mail: karaagac@balikesir.edu.tr H. Kuru e-mail: htopcu@balikesir.edu.tr All superlattices exhibited giant magnetoresistance (GMR). As the ferromagnetic layer thickness increased up to 4 nm, the GMR value increases up to 22 % and then decreases. The superlattices saturated at the lower magnetic layers with increasing ferromagnetic layer thickness. The maxi- mum GMR value was obtained to be 22 % for a superlattice with 375[CoFeNi(4 nm)/Cu(4 nm)]. Keywords Electrodeposition · CoFeNi/Cu superlattices · XRD · VSM · GMR 1 Introduction In 1988, a large magnetoresistance effect, which was named Giant Magnetoresistance (GMR), was discovered in mul- tilayered thin films [1]. After its discovery, the GMR ef- fect begun to be used in technological applications such as sensors, hard disk drives, micro electromechanical systems and magnetoresistive random access memory [2]. Various magnetic structures, such as magnetic superlattices and spin valves, are synthesized at nanometer scales [3]. The elec- trodeposition (ED) process is one of the techniques used to produce such nanostructures. The ED is simpler, cheaper and faster than vacuum techniques such as, the molecu- lar beam epitaxy and the sputtering. The GMR in elec- trodeposited superlattices was first observed in the NiCoCu/ Cu superlattices [4] and the GMR values comparable to those of the films grown by the vacuum systems were ob- tained [5]. The electrodeposited superlattices were consid- erably affected by many deposition parameters such as elec- trolyte pH, room temperature, electrolyte concentration, de- position potential. Making some changes on these parame- ters can affect the GMR values as well as other properties.