  We report a direct observation of magnetic domain evolution near the Verwey
transition (TV) in Fe3O4 films. We found the stripe domains in the
Fe3O4/Mg2TiO4 film while the irregular domains in the Fe3O4/MgO film and the
similar characters of magnetic domains in the vicinity of TV for both samples:
the bigger domain size and the higher contrast of the phase signal below TV and
the more disordered domain images at TV. Remarkably, the magnetic behaviors can
be well understood and the domain-wall energy and the demagnetizing energy can
be calculated from the magnetic domains near TV in the Fe3O4/Mg2TiO4 film. Our
work presents a demonstration of the low temperature magnetic domains and gives
a new perspective to understand the Verwey transition in Fe3O4 thin films.
