Digest Journal of Nanomaterials and Biostructures Vol. 9, No. 3, July - September 2014, p. 1179 - 1185 COMPARATIVE STUDIES OF MORPHOLOGICAL AND MICROSTRUCTURAL PROPERTIES OF ELECTRODEPOSITED NANOCRSYTALLINE TWO-PHASE Co-Cu THIN FILMS PREPARED AT LOW AND HIGH ELECTROLYTE TEMPERATURES U. SARAC a* , M. C. BAYKUL b a Department of ElementaryEducation, Bartın University, Bartın 74100, Turkey b Department of Physics, Eskişehir Osmangazi University, Eskişehir 26480, Turkey In this work, we have studied the effect of the electrolyte temperature on the compositional, structural, and morphological properties of the Co-Cu thin films grown onto ITO coated glass substrates by galvanostatic electrodeposition. The galvanostatic potential-time transients were employed to study the deposition growth process of the films. The compositional analysis which was made using an energy dispersive X-ray spectroscopy (EDX) indicated that the Cu composition in the films enhances with increasing electrolyte temperature. From the X-ray diffraction (XRD) analysis, all of the Co-Cu films were found to consist of hexagonal close-packed (HCP) Co and face-centered cubic (FCC) Cu phase structures regardless of electrolyte temperature. The peak intensities were also changed with electrolyte temperature. It was observed that an enhancement in the electrolyte temperature gives rise to an increase in the average crystallite size of both Cu and Co particles. Atomic force microscopy (AFM) analysis revealed that temperature of the electrolyte significantly affects the surface morphology of the films. Here, several surface roughness parameters such as root mean square (RMS) roughness, average roughness, maximum peak height, and maximum valley depth were also presented as a function of the electrolyte temperature. (Received May 30, 2014; Accepted September 22, 2014) Keywords: Electrodeposited Co-Cu films, AFM, Microstructure, Electrolyte temperature 1. Introduction The properties of Co-Cu films grown at different deposition conditions by electrochemical deposition method have been intensively studied for a long time because of their potential applications in many industrial areas [1, 2]. Electrodeposition has been considered as a feasible alternative technique to the expensive vacuum techniques for preparation of magnetic multilayers and nanocrystalline alloy thin films due to the distinct properties such as simplicity, inexpensiveness, easy scale up, possibility to grow films on irregular surfaces, and relatively high deposition rate [3-11]. It is well known that the microstructural and morphological properties of the films significantly change with the electroplating parameters. Among them, as an important electroplating parameter, the electrolyte temperature in deposition process has a significant effect on the properties of electrodeposited films. However, only a few studies have been carried out on the properties of electrodeposited Co-Cu films prepared at different electrolyte temperatures [12, 13]. To our knowledge, particularly, the analysis of the morphological properties of the electrodeposited two-phase Co-Cu films prepared onto ITO coated glass substrates with respect to electrolyte temperature using AFM has not been reported up to now. The electrolyte temperature is known as one of the most important deposition parameters, because it influences the physical and mechanical properties of electrodeposited thin films such as chemical composition, grain size, texture, and surface roughness, etc. [14]. Therefore, in the present work, the aim is to obtain the Co-Cu films by electrochemical deposition method at various electrolyte temperatures and investigate its effect on the morphological and microstructural properties of the films. Here, it was * Corresponding author: usarac428@hotmail.com