  We examine the magnetic easy-axis directions of stoichiometric magnetite
films grown on SrTiO3:Nb by infrared pulsed-laser deposition. Spin-polarized
low-energy electron microscopy reveals that the individual magnetic domains are
magnetized along the in-plane <100> film directions. Magneto-optical Kerr
effect measurements show that the maxima of the remanence and coercivity are
also along in-plane <100> film directions. This easy-axis orientation differs
from bulk magnetite and films prepared by other techniques, establishing that
the magnetic anisotropy can be tuned by film growth.
