Nonlinear ion transport in glass-forming ionic liquids: Higher harmonic ac currents and electrical creep

• Applicant: Professor Dr. Bernhard Roling
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2010 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 157463299

The nonlinear ionic conductivity of supercooled ionic liquids and of their mixtures with molecular liquids shall be studied by measuring higher-harmonic currents after applying high ac electric fields. In order to generate fields above 100 kV/cm, different electrode configurations will be set up and tested. In mixtures with small amounts of ionic liquid, the nonlinear dynamics of quasi-independent ions will be probed. With increasing ion concentration, interactions between the probe ions will become more and more relevant. A detailed comparison will be drawn between our experimental results and the theoretical results obtained in other projects. In particular, theoretical predictions about the shrinkage of the linear response regime close to the glass transitions will be tested. The aim is to gain new insights into the force-dependent subdiffusive and diffusive ion dynamics during vitrification.

• DFG Programme: Research Units
• Subproject of: FOR 1394: Nonlinear Response to Probe Vitrification