This project explores the origin of magnetic anisotropy in ultrathin iron films deposited on single crystal tungsten substrates using ultra-high vacuum sputtering techniques. The films will be characterized in-situ during deposition and subsequent crystallization using grazing incidence X-ray scattering to monitor the crystallization process and to monitor lattice accommodation and the number and orientation of crystal dislocations generated. Magnetic anisotropy measurements will be made and correlated with microscopic structural features. A second part of the project is devoted to incorporation and study of the effects of rare earth atoms at the iron-tungsten interface. Rare earth atoms at the interface in dilute amounts have the potential to produce large magnetic anisotropy, and this effect will be studied. The dominating importance of interfacial effects in films which are only a few atomic layers thick can in principle be used to tune the magnetic anisotropy and magnetic moment of a given sample to a desired value. Since the mean free path of electrons in these multilayer media may be substantially longer than the layer thicknesses, remarkable electron transport properties, such as the giant magneto resistance effect have been observed. Many of the properties of multilayer ultrathin films are of interest for technological application, especially for data storage either magnetic or magneto optic.
