Creation and Observation of Domain Structures with a Special Kerr Microscope

A Kerr microscope is presented, which on the one hand allows us to make, in a conventional manner, images of domains in thin films with perpendicular magnetic anisotropy. On the other hand, it is possible to heat the sample locally by a focussed laser beam and make images simultaneously. Therefore, it is possible to write domains thermomagnetically and further to observe temperature dependent magnetic reorientations. For demonstration domains have been created thermomagnetically in TbFe multilayers. Writing with low magnetic field leads to domains with a subdomain structure, as it has been found previously by Lorentz microscopy.