In addition to other techniques (see webpage on preparation), we produce our polymer-based nanocomposites by co- and tandem sputtering, involving rf magnetron sputtering of selected polymers such as Teflon from a polymer target and dc sputtering from a metal or alloy target. For magnetic metals, rf sputtering is also used. The resulting polymer matrix is crosslinked, which is often advantageous and may, in particular, improve the mechanical properties compared to the original polymer. In order to find suitable polymers for sputter deposition, we investigated in detail the interaction of low energy ions with polymers . The crucial point is the competition between chain scission and crosslinking. Polymers with a high sputter rate should exhibit a low crosslinking tendency. Teflon (PTFE) turned out to exhibit a sputter yield which is about two orders of magnitude above that of most other polymers. This polymer is particularly suitable for sputtering and preparation of metal-containing nanocomposites.

Besides polymers also inorganic materials can serve as a dielectric matrix. Therefore, also rf sputter processes and reactive sputtering are well established in our group for inorganic materials like SiO₂, TiO₂ and AlN.

In addition to experimental work, the co-deposition processes were also investigated based on computer simulations. Recent studies were performed in close cooperation with the group of Michael Bonitz from theoretical physics in Kiel. 

TEM micrograph of superparamagnetic FeCo nanoparticles in an SiO₂ matrix prepared by co-sputtering.

Selected publications

Xiong, J.; Zubair Ghori, M.; Henkel, B.; Strunskus, T.; Schümann, U.; Kienle, L.; Faupel, F.: Controlling surface segregation of reactively sputtered Ag/TiOx nanocomposites, Acta Materialia 74 (2014) 1-8.

Chakravadhanula, V.S.K.; Hrkac, T.; Zaporojtchenko, V.; Podschun, R.; Kotnur, V.G.; Kulkarni, A.; Strunskus, T.; Kienle, L.; Faupel, F.: Nanostructural and functional properties of Ag-TiO2 coatings prepared by co-sputtering depostion technique, Journal of Nanoscience and Nanotechnology Vol. 11 (2011) 4893-4899.

Kulkarni, A.; Chakravadhanula, V.S.K.; Duppel, V.; Meyners, D.; Zaporojtchenko, V.; Strunskus, T.; Kienle, L.; Quandt, E.; Faupel, F.: Morphological and magnetic properties of TiO2 / Fe50Co50 composite films, Jornal of Materials Science Vol. 46 Issue 13 (2011) 4638.

Zaporojtchenko, V.; Podschun, R.; Schürmann, U.; Kulkarni, A.; Faupel, F.: Physico-chemical and antimicrobial properties of co-sputtered Ag-Au /PTFE nanocomposite coatings, Nanotechnology 17(19) (2006) 4904-4908.

Schürmann, U.; Takele, H.; Zaporojtchenko, V.; Faupel, F.. Optical and electrical properties of poymer metal nanocomposites prepared by magnetron co-sputtering, Thin Solid Films 515(2) (2006) 801-804.

Schürmann, U.; Hartung, W.A.; Takele, H.; Zaporojtchenko, V.; Faupel, F.: Controlled syntheses of Ag-PTFE nanocomposite thin films by co-sputtering from two magnetron sources, Nanotechnology 16(8) (2005) 1078-1082.

Computer simulations

Abraham, J.W.; Strunskus, T.; Faupel, F.; Bonitz, M.; Molecular dynamics simulation of gold cluster growth during sputter deposition, Journal of Applied Physics 119 (2016) 185301 ; "Editors' Pick".

Schwartzkopf, M.; Santoro, G.; Brett, C.J.; Rothkirch, A.; Polonskyi, O.; Hinz, A.; Metwalli, E.; Yao, Y.; Strunskus, T.; Faupel, F; Muller-Buschbaum, P.; Roth, S.V.; Real-Time Monitoring of Morphology and Optical Properties during Sputter Deposition for Tailoring Metal-Polymer-Interfaces, ACS Appl. Mater. Interfaces online (2015) .

Abraham, J.W.; Kongsuwan, N.; Strunskus, T.; Faupel, F.; Bonitz, M.; Simulation of nanocolumn formation in a plasma environment, Journal of Applied Physics 117 (2015) 14305.

Rosenthal, L.; Strunskus, T.; Faupel, F.; Abraham, J.W.; Bonitz, M.: Kinetic Monte Carlo Simulations of Cluster Growth and Diffusion in Metal-Polymer Nanocomposites, Complex Plasmas, Springer Series on Atomic, Optical, and Plasma Physics82 (2014) 321-370.

Kornich, G.V.; Betz, G.; Zaporojtchenko, V.; Bazhin, A.I.; Faupel, F.: Molecular dynamics simulations of low energy ion sputtering of copper nano-dimensional clusters on graphite substrates Nuclear Instruments and Methods, Physics Research B, 227(3) (2005) 261-270.