Magnetic anisotropies can be modified locally by intense electron beams wit
h keV energy. In ultrathin epitaxial Co films grown on Pt(111), switching o
f the easy axis from parallel to perpendicular to the surface can be induce
d, and the domain size can be enlarged by one order of magnitude. (C) 1998
American Institute of Physics. [S0003-6951(98)03150-7].