STRUCTURAL-PROPERTIES OF CO AU SUPERLATTICES INVESTIGATED BY HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY/

Ion-beam-sputtered and electron-beam-evaporated Co/Au multilayers have been investigated with high-resolution transmission electron microsco py. The multilayers are found to exhibit a strong {111} texture and to contain Co predominantly in the cubic (fcc) phase. Misfit dislocation s were directly observed and found to be located near the Co/Au interf aces. Structural features correlate with the magnetic anisotropy. Larg e crystalline units (vertical columns with approximately 50 nm diamete r reaching throughout the superlattice) are composed of small regions, a few nanometers in size (nanocrystallites), which are tilted towards each other by a few degrees. The microstructure of the large units re mains unchanged for all investigated samples. The average size of the nanocrystallites and their mutual tilting angle vary systematically an d are obviously correlated to the magnetic anisotropy. A high-crystall ine quality (large nanocrystallites and small tilt angles) increases t he value of the magnetic anisotropy constant K(u)eff. This behavior is unique for the presently investigated Co/Au multilayers independent o f the fabrication technique. Moreover, these magnetostructural correla tions may as well be valid for other magnetic/nonmagnetic metal superl attices.