Regensburg 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MA: Fachverband Magnetismus
MA 29: Magnetic Semiconductors I
MA 29.5: Talk
Thursday, March 25, 2010, 16:15–16:30, H22
Secondary phase formation in (Zn,Mn)O and its influence on the magnetic properties — •Gillian Kiliani1, Mikhail Fonin1, Ulrich Rüdiger1, Reinhard Schneider2, Dimitri Litvinov2, and Dagmar Gerthsen2 — 1Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany — 2Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie, 76128 Karlsruhe, Germany
ZnO is a wide gap semiconductor which attracted a renewed attention as a material for possible spintronic applications after Dietl et al. calculated Curie temperatures above room temperature for transition metal doped ZnO [1].
(Zn,Mn)O thin films were prepared by radio frequency magnetron sputtering on Al2O3(0001) and SiO2/Si(100) substrates from a composite, partially oxidized ZnMn target. Sputtering was performed in Ar or N2, since nitrogen is considered to enhance ferromagnetism in the (Zn,Mn)O system [2]. Structural properties were investigated by different techniques of transmission electron microscopy and X-ray diffraction. The formation of at least one secondary phase in samples with high Mn content could be observed, which had significant influence on the magnetic properties as shown by magnetization measurements. Ferromagnetism and exchange bias were observed in samples with high Mn concentration, suggesting the presence not only of a ferromagnetic, but also of an antiferromagnetic phase.
[1] T. Dietl et al., Science 287, 1019 (2000).
[2] K. R. Kittilstved et al., Nat. Mater. 5, 291 (2006).