Nanopatterning of surfaces by ion bombardment
Ion bombardment of solid surfaces very often leads to the development of highly periodic nanopatterns such as nanodots and ripple-like structures. Their characteristic features (orientation, periodicity, etc.) depend strongly on the material being bombarded and the ion-beam parameters (energy, angle of incidence, ion current density). Generally, these phenomena are believed to be related to (and caused by) the interplay between ion erosion and diffusion of adatoms (vacancies) which induces a surface re-organization. Several promising applications for such structures are envisaged.
In this context, the dynamic evolution of such nanostructures will be studied for various materials and a wide range of ion-beam parameters. Specifically, the temporal dynamics of these patterns as function of irradiation time (fluence) will be investigated for the different experimental parameters. These results should be evaluated with respect to current theoretical concepts of the ion-induced morphological evolution of surfaces.
The experiments will be performed in two setups:
(i) A dual-beam focused ion beam system (at IFOS) that comprises a scanning electron microscope (SEM) and highly focused ion beam. This combination enables an in situ observation by SEM of the surface morphology created by the ion beam.
(ii) An ultrahigh vacuum apparatus which is equipped with a low-energy ion source and a scanning tunneling microscope (STM). In this system, the temporal evolution of the formed nanopatterns can be studied by STM upon consecutive ion-irradiation steps.
Contact
apl. Prof. Dr. Hubert Gnaser
Characterization of protein films on glass surfaces
Protein films form on nearly all surfaces as soon as they are stored under humid, non-sterile conditions. They transform in a later stage to biofilms which are present in such different environments as the oral cavity (plaque on teeth) or in food or pharmaceutical packages.
In this context the interaction between proteins and substrates will be studied by means of a variety of surface analytical tools. As substrate different forms of glass will be chosen because of its importance in pharmaceutical packaging. Different pretreatments such as ion etching will be persued as well. Secondary ion mass spectrometry (ToF-SIMS, IFOS) will be the major tool to study the chemical composition as a function of surface position and depth.
These studies will be compared to scanning force spectroscopy results (Ziegler) by which the binding force between proteins and substrate can be determined. Furthermore, methods such as static (IFOS) and dynamic (Ziegler) contact angle as well isoelectric point measurements will be applied. This will allow to develop a detailed picture of protein interaction as a function of hydrophilicity and electrostatics.
Contact
Prof. Dr. Christiane Ziegler
OPTIMAS and Carl Zeiss Foundation
The State Research Centre for Optics and Material Sciences (OPTIMAS) invites applications for funded Ph.D. positions supported by the Carl Zeiss Foundation. The whole program consists of eight interdisciplinary research projects. Each of the eight projects will employ two doctoral candidates, one in each of the two partner research groups. The positions provide monthly stipends for a fixed term of three years. Following you find those positions that are still available.
A successful candidate should hold an M.Sc. or equivalent qualification in the indicated scientific area or a related research field. Applications with the usual supporting material should be submitted asap to the leader of the participating research group. Contact information is provided with the individual project descriptions below. Additional background information on the participating research groups and their scientific scope can be found on the indicated homepages. Further information about the OPTIMAS State Research Centre is available at optimas.uni-kl.de.
The University of Kaiserslautern is endeavouring to increase the proportion of women in research and education. Qualified female scientists are especially encouraged to apply. Individuals with handicaps are preferentially hired (please submit appropriate documents). Applicants with children are welcome.
Applications may be submitted in either electronic or paper form. Paper applications should include only copies of documents (certification is not necessary), as application materials will not be returned. Please do not include folders or document covers. Documents will be disposed of in accordance with data privacy protection standards at the conclusion of the recruiting process.