Condensed Matter Seminar Announcement Prof. Christian Teichert Montanuniversität Leoben, Austria " Self-organized semiconductor surfaces as templates for nanostructured magnetic thin films " Date: Thursday, May 5, 2005 416 Phy/Geo Time: 4:10 pm. Abstract: Spontaneous pattern formation during epitaxial growth or ion erosion of semiconductor wafers offers an elegant route towards large-area nanostructured surfaces. In the case of semiconductor heteroepitaxy strain relief leads to the formation of nanofaceted three-dimensional crystallites, which may self-organize into quasiperiodic arrays [1]. By tuning substrate miscut and film thickness or growing superlattices a variety of patterns with different symmetries can be obtained as will be summarized for the model system of SiGe on Si(001). Since these self-organized nanostructure arrays cover the entire wafer on which they were grown, they can serve as large-area nanopatterned substrates for subsequent deposition of magnetic thin films. It will be demonstrated that such templates allow to study correlations between magnetic and chemical interfacial roughness as well as the influence of pattern symmetry on the magnetic anisotropy of thin Co films [2]. Further, arrays of isolated nanomagnets can be fabricated by shadow deposition onto selected facet types. X-ray magnetic c ircular dichroism measurements using a photoemission electron microscope (XMCD-PEEM) reveal the in plane magnetization of the single domain nanomagnets as well as possible coupling between them [3]. [1] C. Teichert, Phys.Rep. 365 (2002) 335-432. [2] C. Teichert, Appl. Phys. A 76 (2003) 653-664. [3] A. M. Mulders, et al., Phys. Rev. B (2005), in print.

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