Preparation and Caracterization of Electrodeposited Magnetic Multilayrs

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Fabrication of atomically controlled Co/Pt and Co/Cu magnetic multilayrs by electrodeposition has been discussed on the basis of a nucleation-growth mechanism and experimental observations. Reflection electron microscopy studies of electrodeposited Co, Cu/Pt (111) ultrathin layrs have revealed a heteroepitaxial and simultaneous multinuclear multilayr growth in a range from seversl up to some ten monolayr coverages at room temperature, which has been dependent upon the crystallization overpotential. Cross-sectional transmission electron microscopy observations, X-ray diffraction, and Auger and photoelectron spectroscopy experiments have provided direct evidence for composition modulation across successive layrs in Co/Pt and Co/Cu nanometer-multilayred structures prepared by electrodeposition under potential control. The growth and structure of the multilayrs have been dependent upon the deposition overpotential. "Giant" magnetoresistance of more than 20% has been observed at room temperature in a (111) textured Co/Cu multilayred nanostructure containing a nominal Cu spacer layr thickness of 10 nm. This value is nearly comparable to those previously reported in vapor-deposited multilayrs. Further studies on the crystallization kinetics of nucleation and growth are necessary to obtain improved quality of the nanometer-multilayred structures. Electrodeposition under precise crystallization overpotential and current density control will be a highly competitive technique for the preparation of magnetic multilayrs, and has a potential to create multilayred structures exhibiting unusual magnetic properties previously unavailable by vapor-phase deposition.