Misfit dislocations are thermodynamically stable in epitaxial films above a critical thickness, which depends mainly on the misfit magnitude between the film and substrate. The formation of dislocations does not occur immediately when the critical thickness is exceeded since kinetic factors are involved which are not adequately understood. This grant examines the role of misfit dislocations and strain in affecting behavior of magnetic films. The kinetics of dislocation nucleation in epitaxial thin films is pursued with an aim towards developing an in-situ method for monitoring misfit dislocation formation. The Magneto-optic Kerr (MOKE) effect is employed as a probe that is sensitive to the presence of small strains in magnetic films. This is used to characterize misfit strains and dislocations on epitaxial nickel/copper films. Other techniques employed are electron microscopy and secondary electron spin polarization analysis to determine the kinetics of dislocation formation. %%% The homogeneous strain of lattice mismatch and the highly non- uniform strains around dislocations have dramatic effects on magnetic properties. This research is directed towards developing a better understanding of the formation of misfit dislocations and their effects on magnetic films. An in-situ monitoring technique during film growth could result from the research.
