Cobalt-based Heusler compounds in magnetic tunnel junctions [Elektronische Ressource] / Daniel Ebke. Fakultät für Physik - Abt. Experimentalphysik : Dünne Schichten und Nanostrukturen

DANIEL EBKECOBALT-BASEDHEUSLERCOMPOUNDSINMAGNETIC TUNNELJUNCTIONSBIELEFELD UNIVERSITYThis work was done by myself. Text and figures were partly taken from corresponding publi-cations originate directly from this work.(Daniel Ebke)Reviewers:Prof. Dr. Andreas HüttenProf. Dr. Walter PfeifferCopyright © 2010 Daniel Ebkebielefeld university, department of physicsthin films & physics of nanostructuresPh.D. thesisFirst printing, July 2010ContentsPublications and Conferences 9The optimal seed layer system 13Optimization of the Heusler layer 21Various Co-based Heusler compounds 29Transport properties 55Industrial applicability 79Conclusions 87Appendix 913Schaffe, schaffe Heusler baue!5IntroductionSpintronic devices have attracted a lot of attention in recent yearsdue to possible new applications, e.g., a magnetic random access1 1memory (MRAM), logic and sensors. The spin of the electrons S. A. Wolf, Science 294,1488(2001); and G. A. Prinz, Sci-is used as an additional degree of freedom in contrast to com-ence 282, 1660 (1998)mon electronic devices. The main constituent of many spintronicdevices is the magnetic tunnel junction (MTJ) where two ferro-2 2magnets are separated by a thin insulating tunnel barrier. The J. S. Moodera et al., Phys.Rev. Lett. 74,3273 (1995); andresistance of such a device depends on the magnetic orientationM. Julliere, Phys. Lett. A 54,of the ferromagnets.