| MaNEP News |
| PSI - EMPA / Improved Pulsed Laser Deposition (PLD) set up | ||
 by Dr Anke Weidenkaff (EMPA) et al.PLD is known as an especially suitable technique for the preparation of thin epitaxial films with complex stoichiometry. However, for complex oxide systems this method often yields anion-deficient films, which need to be annealed afterwards. In our work - focused on the preparation of perovskite-type oxynitrides - we use two modifications of PLD to overcome this limitation : |
1. In pulsed reactive crossed-beam laser ablation (PRCLA) a synchronised gas pulse crosses the plasma plume close to its origin (Fig. 1). This adaptation allows to have an additional source of active anionic species (oxygen or nitrogen) and to increase the plasma ionization degree. [ click for details ] |
2. A recent addition to our PLD setup includes a radio frequency (RF) plasma beam (Fig. 2), which acts as a source of a highly reactive anionic species in the deposition process. This could give us a better control of the anionic composition of the growing film. [ click for details ] |
| Short comment / Recent research into single layer graphene | ||
 by Dr Peter Armitage, University of Geneva Again! Research into the myriad forms that elemental carbon can assume continues to amaze. Recently researchers have been able to isolate stable single atomic layers of honeycomb patterned graphitic carbon (previously believed to be thermodynamically unstable) and are now beginning to investigate some of their fascinating transport properties. Such samples show extraordinarily high |
mobilities (> 104cm2V-1s-1) and a universal minimum conductance near 4e2/h. In this so-called 'graphene' the lack of an even weak interlayer tunneling causes the in-plane band dispersion to become perfectly linear and therefore characterized by an electron effective mass of zero. Moreover, there is a two-fold band degeneracy near the Fermi energy which can be expressed as a pseudo-spin degree of freedom. This means that electrons in graphene become governed by an equation isomorphic to the Dirac equation of relativistic particles - with an effective | speed of light ~1/400 the actual speed of light - and opens the possibility that elementary particle physics can be probed in table top experiments ! Among other things a consequence of these features is an unusual quantization condition for the quantum hall effect. Research in this area is ongoing and promises to be very exciting... Ref[1] K.S. Novoselov et al. Nature 438, 197-200 (2005). |
| FNS Media Training / I am a scientist, how do I talk to journalists ? | ||
| What are the expectations of a journalist ? How do I prepare for an interview ? Questions you may face when asked to meet a journalist... Which happens more often as science is now a regular subject of public | debate. Addressing this evolution, the FNS offers a new very practical media course for researchers. Sessions in French : June 16 and 17, 2006 September 1 and 2, 2006 in Lausanne. |
Sessions in German : June 16 and 17, 2006 August 25 and 26, 2006 in Lucerne. Prize for FNS supported researchers : SFr. 300.- [ Infos : German - French ] |
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