The electrical and optical properties of rodlike fd-virus particles (L = 880 nm, D = 9 nm) are investigated by magnetic and electric birefringence experiments and supplemented by electric field light-scattering measurements. In aqueous suspension the fd-virus particles are negatively charged and surrounded by diffuse counterion clouds. The examinations are performed at very low ionic strength (10"6 M). Under these conditions a liquid crystalline phase already occurs at fd-particle concentrations above 0.6 mg/mL. In magnetic fields the rodlike fd-virus is aligned parallel to the magnetic field due to its diamagnetic anisotropy. Almost complete particle alignment in magnetic fields is obtained for liquid crystalline samples, and the saturation value of the birefringence is determined. The application of electric fields results in a polarization of the counterion clouds and a statistical orientation of the dispersed particles. In low electric fields Kerr behavior is found, providing the electric anisotropy Aotet of a single rod. At higher electric fields the diffuse Debye cloud is partly stripped away and a complete particle orientation is hindered. Electric field light-scattering investigations yield quantitatively the decrease of the electric anisotropy Aoiei in high electric fields.

No abstract

No abstract

We have grown doped diamondlike carbon (DLC) thin films on Ni and Si substrates by mass separated low energy ion beam deposition. The current-voltage characteristics of these films and also a P-doped DLC / B-doped DLC diode-like device were measured. Doped DLC films show a higher electrical conductivity, which we interpret by hopping conductivity due to an increased density of localized states rather than a shift of the Fermi level. We also present first results on doping modulated DLC multilayers deposited on Si substrates. The dopant concentration profiles were analyzed by Rutherford Backscattering for63Cu dopant atoms and by neutron depth profiling for a10B doped multilayer.

No abstract