MAGNETISM AND MORPHOLOGY OF FE CU(111) FILMS BELOW 2-DIMENSIONAL PERCOLATION/

The magnetic properties of gamma-iron films on Cu(111) below the two-d imensional percolation threshold of about 1.4 monolayer are investigat ed. Iron on flat Cu(111) surfaces forms triangular patches, while it f orms stripes along step edges on vicinal surfaces. The films exhibit a n easy magnetization axis perpendicular to the film plane and magnetic hysteresis at sufficiently low temperatures. The magnetization curves of the triangular iron patches are discussed in terms of Ising superp aramagnetism. From Kerr hysteresis loops, we deduce that the first ani sotropy constant K-1 in the superparamagnetic films is of order 0.345/-0.020 MJ/m(3). (C) 1997 American Institute of Physics.