|Budget Amount *help
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2001: ¥2,100,000 (Direct Cost: ¥2,100,000)
Magnetic metal nanostructures, since the discovery of perpendicular magnetic anisotropy, magneto-optical Kerr effect and giant magnetoresistance, have attracted considerable attention for potential applicability to high density magneto-optical recording media or magnetoresistive sensor devices. Most magnetic nanostructures have been fabricated by sputtering or molecular beam epitaxy, which have proved to be the most suitable for the controlled preparation of high-quality structures on an atomic scale. Electrodeposition may also be more promising for all practical purposes, given the efficiency and the simplicity of the required equipment, and seems highly likely to lead to exciting developments as an alternative to vacuum-based fabrication techniques. We have presented the first direct evidence for composition modulation across successive layers in a Co/Pt nanometer-multilayered structure grown on a Pt (111) substrate by electrodeposition under potential control. Giant magnetoresistance and oscillatory antiferromagnetic interlayer coupling have been observed in an fcc (111) textured Co/Cu multilayered nanostructure, while for a heterogeneous Co-Cu alloy, a large saturation magnetoresistance of more than 20% has been achieved at room temperature. Multilayered fcc Co/Pt and CoNi/Pt nanostructures, respectively, exhibit a remanent perpendicular magnetization and a large magnetic coercivity, which depend on the multilayer growth mechanism. Moreover, an array of CoNi/Pt multilayered nanowires has been prepared by template eledctrodeposition in a nanoporous anodic aluminum oxide membrane, leading to a magnetic sharp anisotropy due to extremely high aspect ratio structures. Further studies on the growth kinetics and mechanism are necessary to achieve improved structural and magnetic qualities in the electrodeposited multilayered nanostructures, and also apply to patterning on the nanometer scale.