A new ultrahigh vacuum instrument allowing in situ Kerr microscopy and
scanning tunneling microscopy is described. The Kerr microscope has a
spatial resolution of about 1 mu m. First experimental results are re
ported on the magnetism of a 5 mu m wide stripe consisting of six atom
ic layers of Fe grown in situ by molecular beam epitaxy on a W(110) su
rface. (C) 1997 American Institute of Physics.