Spin structure of antiferromagnetic thin films investigated with spin-polarized scanning tunneling microscopy [Elektronische Ressource] / von Chunlei Gao

SPIN STRUCTURE OF ANTIFERROMAGNETIC THINFILMSINVESTIGATED WITHSPIN-POLARIZED SCANNING TUNNELINGMICROSCOPYDissertationzur Erlangung des akademischen GradesDr. rer. nat.vorgelegt derdie Naturwissenschaftliche Fakultat¨ IIInstitut fur¨ Physikder Martin Luther Universit at¨ Halle Wittenbergvon Herrn Chunlei Gaogeboren am 16.03.1977 in ChinaGutachter:1. Prof. Dr. Jur¨ gen Kirschner2. Prof. Dr. Henning Neddermeyer3. Prof. Dr. Markus MorgensternHalle (Saale), 2006verteidigt am 18.12.2006urn:nbn:de:gbv:3-000011615[http://nbn-resolving.de/urn/resolver.pl?urn=nbn%3Ade%3Agbv%3A3-000011615].2AbstractThe objective of this thesis is to investigate noncollinear antiferromagnetic surfacespin structures with spin polarized scanning tunneling microscopy (Sp STM). Thespin polarized measurements are realized by using a soft magnetic ring as the scan ning electrode. A complete separation of topographic and spin signal is achievedthrough operating the Sp STM in the differential magnetic mode. Two systems√ √◦were studied. First, a large ( 10×2 10)R18.4 reconstruction of Mn films witha noncollinear spin structure was found on Fe(001). By combining maps of thespin polarization of two orthogonal directions, the vector field of the polarizationin the unit cell was fully constructed. Nearly antiparallel alignments of surfaceMn moments was resolved on atomic scale.