FePt magnetic multilayers electrodeposited from non-aqueous liquids

Abstract

FePt magnetic multilayers were pulse electrodeposited from the mixture of ammonium hexachloroplatinate and iron dichloride in ionic liquids based on glycol (EG) and 1-ethyl-3-methylimidazolium chloride (EMIC). The chelate effect and electrochemical behaviour of the EMIC with the ions were determined by ultraviolet–visible spectra and cyclic voltammetry respectively. The iron atomic content in the FePt films ranged from 0·4 to 81·0 at-% when deposition potentials changed from 1·0 to −2·0 V(Ag/AgCl) in electrodeposition system with the EG (50 mL), ammonium hexachloroplatinate (25 mM L−1), iron dichloride (175 mM L−1) and EMIC (25 mM L−1) at 393 K. Fe50Pt50 thin films with smooth surface (50 at-% iron layer in FePt film) and the multilayer cross-section were obtained. Fct structural FePt multilayer was obtained based on X-ray diffraction pattern. Magnetic hysteresis loops showed that the multilayer possessed a magnetic anisotropic behaviour.