Correlation between microstructure and magnetic properties of electrodeposited Co/Pt multilayers V. Georgescu * , M. Georgescu Faculty of Physics, Al. I. Cuza University, 11 Copou Blvd., Iasi 6600, Romania Abstract Our purpose was to prepare by electrolysis Co/Pt multilayers and to study their magnetic properties in correlation with microstructure. Co/Pt multilayers with periods of (1.3–7.9) nm were electrodeposited on (1 0 0)-textured Cu foils with a 50 nm Pt buffer layer. Effective magnetic anisotropy and coercive field were found to depend on Co layer thickness (for a series of multilayers with 1 nm thickens of Pt layer). These films were characterized using atomic force microscope and X-ray diffraction techniques. Depending both on the periodicity of multilayer and the preparation conditions electrodeposited Co/Pt multilayers contain the fct, as well as the hcp and amorphous phase. The shape of the differential hysteresis loop (analyzed by fast Fourier transform technique) reflects peculiarities in switching properties of the magnetization in multilayers in the presence of interface anisotropy. Ó 2002 Elsevier Science B.V. All rights reserved. Keywords: Cobalt; Platinum; Magnetic films; Metallic films; Atomic force microscopy; Magnetic measurements 1. Introduction Co/Pt multilayers have been extensively studied in recent years for reasons of scientific interest and due to their applications in magnetic and magneto- optical recording [1–3]. Most of these multilayers have been prepared by sputtering or molecular beam epitaxy techniques. Our purpose was to prepare Co/Pt multilayers by electrolysis and to study their magnetic properties (particularly inter- face magnetic anisotropy and perpendicular an- isotropy) in correlation with microstructure, with a view to obtain technological applications. This preparation method has an advantage in practical simplicity and economically attractive technique, but requires a very good knowledge of the prepa- ration parameters to acquire reproducible mag- netic properties. The study has been correlated with our previous work on preparation and properties of multilayers [4,5]. 2. Experimental details Multilayer films were electroplated by alter- nately depositing Co and Pt from a single complex bath by switching the cathode potential between two characteristic values (with potentiostatic con- trol). The electrolytic bath contains 40.0 gl 1 CoSO 4  7H 2 O, 0.66 g l 1 K 2 PtCl 6 , and 40.0 g l 1 H 3 BO 3 . The pH value of the bath was 4.0 and the temperature was ð30  0:5Þ °C. The deposi- tion rate was monitored by the deposition para- meters and it was determined from X-ray diffraction (XRD) measurements [4,5]. Films were deposited Surface Science 507–510 (2002) 507–511 www.elsevier.com/locate/susc * Corresponding author. Fax: +40-32-213930/201150. E-mail address: vgeor@uaic.ro (V. Georgescu). 0039-6028/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0039-6028(02)01294-3