Abstract
Our recent experimental results on the surface magnetic structures of Cr(001) films epitaxially grown on Au(001) surface were reviewed. Magnetic imaging of the Cr(001) films was performed at room temperature by spin-polarized scanning tunneling spectroscopy. It is found that two-step growth of Cr layers at two different growth temperatures results in a chemically clean and atomically flat surface. We observed distinct magnetic contrasts by using differential conductivity maps with Fe-coated W tips. The results are consistent with the topological antiferromagnetic (AF) order in the Cr(001) film surface. In addition, the existence of domains with different quantization axes of AF order and the narrow domain-wall width (∼6 nm) near screw dislocations were found. The quantization axis of each domain is obviously correlated with the step direction. The screw-dislocation distance may play an important role in determining the domain wall width. These experimental results are subject to high-density steps and screw dislocations.
