Michael Stoermer Ph.D.
Dr. Michael Störmer is a scientist in the department of nanotechnology at the Institute for Materials Research at GKSS, which is one of the 15 members of the Helmholtz Association of German Research Centres (HGF). Dr. Störmer’s work focuses on the development of thin films for X-ray optical applications and corrosion protection of lightweight materials, especially magnesium-based alloys.He started his scientific work at the Institute of Materials Physics (University of Göttingen). In 1998, he graduated with a PhD thesis in metal physics on experiments with thin films. During this time he investigated the microstructure, phase formation, structure and internal stress of laser-deposited metallic alloys. The results showed that metallic films and multilayers were far away from equilibrium.
Since 1999, he has been working at GKSS, doing research on nanostructured mono- and multilayer systems, which are optical elements to improve the performance of X-ray optical systems by collimation, beam shaping, beam guidance and monochromatization. The improvement of X-ray mirrors was focussed on three different fields: multilayers for X-ray diffraction (XRD), analysers for the improved detection of light elements with X-ray fluorescence spectrometry (XRF) and total-reflection mirrors for free-electron lasers. The successful work in the field of X-ray mirrors for laboratory sources led to the foundation of the company Incoatec GmbH, Geesthacht/Germany in 2002.
At GKSS, his current activity is the development of large total-reflection mirrors for free-electron lasers (e.g. VUV-FEL: FLASH at DESY in Hamburg) and for synchrotron storages. State-of-the-art magnetron-sputtering technology is used, by means of which it is possibleto deposit nanostructured mono- and multilayer films with a high reflectivity at different photon energies, achieving good uniformity in thickness and a very low roughness over the whole optical area. At the moment the deposition length is 500 mm, but it will be increased to more than 1 m. Due to the working range of FLASH (50-200eV), carbon has been selected as a suitable material for the total-reflection mirrors. After deposition, the variation in film thickness was investigated by X-ray reflectometry (XRR). Over the whole length of 500 mm, the uniformity in thickness is better than 2%. The reflectivity is close to the theoretical limit. Further investigations by means of optical profilometry and atomic force microscopy have shown that the surface roughness before and after deposition is more or less the same. It is below 5Å at each observed position of the mirror. So, the deposition process is very precise and the film uniformity is excellent.
Lightweight materials are more and more frequently applied in the automotive and aviation industries. Magnesium exhibits an extraordinarily low density, but its industrial use is still limited by its relatively poor corrosion behaviour. PVD-Coatings are a good opportunity and a promising path, because they could act as a protector for the underlying material. The corrosion-protective films are prepared by means of magnetron sputtering with a thickness of some micrometers. Corrosion behaviour, structure, morphology and microstructure are investigated to understand the corrosion process and to find an acceptable and user-oriented solution with regard to a low corrosion rate.
Books“Nanostructured Multi-layers for applications in X-ray optics“
The Dekker Encyclopedia of Nanoscience and Nanotechnology, Marcel Dekker Inc., New York, (2006)
Nano Article - 120041325 Encyclopedia of Nanoscience and Nanotechnology
Important Articles• M. Störmer, C. Michaelsen, J. Wiesmann, P. Ricardo and R. Bormann, Nanostructured Multi-layers for applications in X-ray optics, The Dekker Encyclopedia of Nanoscience and Nanotechnology, Marcel Dekker Inc., New York, (2006).
• L. Juha, M. Störmer et al. , Radiation damage to amorphous-carbon optical coatings, SPIE Proc. 5917 (2005) 59170F.
• D. Häußler, E. Spieker, S. Yang, W. Jäger, M. Störmer, C. Michaelsen, R. Bormann and G. Zwicker, TEM characterization of La/B4C multilayer systems by geometric phase method, phys. stat. sol. (a) 202(12) (2005) 2299-2308.
• M. Störmer, A. Liard-Cloup, F. Felten, S. Jacobi, B. Steeg, J. Feldhaus and R. Bormann, Investigations of large X-ray optics for free electron lasers, SPIE Proc. 5533 (2004) 58-65.
• Krebs, H.-U.; Weisheit, M.; Faupel, J.; Sueske, E.; Scharf, T.; Fuhse, C.; Stoermer, M.; Sturm, K.; Seibt, M.; Kijewski, H.; Nelke, D.; Panchenko and E.; Buback, M., Pulsed Laser Deposition (PLD) - A versatile thin film technique, Advances in Solid State Physics 43 (2003) 505-518
• S. Jacobi, B. Steeg, J. Wiesmann, M. Störmer, J. Feldhaus, R. Bormann and C. Michaelsen, Characterization of amorphous carbon films as total-reflection mirrors for the XUV free electron lasers, SPIE Proc. 4782 (2002).
• M. Schuster, H. Göbel, L. Brügemann, D. Bahr, F. Burgäzy, C. Michaelsen, M. Störmer, P. Ricardo, R. Dietsch, T. Holz and H. Mai, Laterally graded multilayer optics for X-ray analysis, Proc. SPIE 3767-27 (1999) .
• C. Michaelsen and M. Störmer, D8 Advance Cr-K Göbel Mirrors for improved resolution in X-ray reflectometry investigations, Lab Report XRD 30 (1999).
By this Researcher