Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Novel Materials

Research

 

Novel Materials

Physical properties

Novel materials may show special electrical, thermal and magnetic but also mechanical and optical properties. We investigate transport phenomena, i.e. the movement of charge carriers, from the spin of the charge carrier or the rate of heat flow in

Our current research topics are

  • thermoelectric effects and heat conduction
  • quantum- and spin effects in the transport of electrons
  • and emergent phenomena in the charge transport, such as charge density waves and superconductivity.

To this end, we use a distinct measuring setup for the determination of the electrical conductivity, the magnetoresistance and the electrical noise. For a full thermoelectrical characterization we measure the thermal conductivity and the Seebeck coefficient, using various methods. The measurements are commonly performed as a function of the temperature and the electrical and magnetic fields. The temperature range currently spans from cryogenic temperatures (16 mK) up to room temperatures (300 K) and magnetic fields up to 12 T are in use.

The interpretation of the results often succeeds only due to the exact knowledge of the crystal- and microstructure, possible atomic defects and imperfections and boundary (or surface structure) nature. Therefore, we carry out structure and topography investigations by means of transmission/electron microscopy, atomic force microscopy and optical microscopy, and we develop "lab on the chip" approaches.
 

Nanopatterning

In the Novel Materials group we use modern methods for the fabrication of nanostructures, such as "top down"-lithography using electron or atomic force microscopes, "bottom up" growth methods, or etching techniques including self-organizational effects.