Creation and Observation of Domain Structures with a Special Kerr Microscope

Abstract

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.

Real Time Image Processing during Observation of Magnetic Domain Structures by Kerr Microscopy

“…1) consists of a Kerr microscope [1,2], a CCIR camera with an 8-bit framegrabber (768 Â 576 pixels and 25 frames per second), a 16-bit digital camera (784 Â 520 pixels and 2 frames per second), a PC equipped with Pentium II Celeron 533 MHz processor and AGP "dualhead" graphic card, two monitors and a bipolar power supply for an electromagnet. The cameras and power supply are all controlled by computer.…”