IN-SITU SCANNING-TUNNELING-MICROSCOPY OBSERVATION OF SURFACE EVOLUTION IN MAGNETICALLY COUPLED CO CU MULTILAYERS/

A series of bilayers of the form Cu(100)/[Co(21 Angstrom)/Cu(21 Angstr om)](n) were grown by both ion beam and DC magnetron sputtering techni ques. Scanning tunneling microscopy images of the developing layers de monstrate a marked difference in the way in which roughness evolves th rough the films, The higher energy ion beam sputtered systems show a n onconformal roughness that is characterized by comparatively large lat eral length scales. The less energetic magnetron-formed systems exhibi t an island-upon-island growth that is conformal from layer to layer. Kerr effect measurements show that the former is ferromagnetically cou pled and the latter is antiferromagnetically coupled. An explanation i s presented that attributes the differences in roughness to the potent ial barriers at step edges. Adatom mobility and incident energy are sh own to be the determining factors for this kind of conformal growth. ( C) 1996 American Institute of Physics.