The activity in the domain of disordered systems consists mainly in the studies of the conduction mechanisms involved in macroscopic samples which conserve its nanometric-scale properties, that is networks of nano-objects obtained by self-organization in surface. Regular networks of nano-objects, which are an experimental realization of the Anderson model, should exhibit a metal-insulator transition as a function of the disorder parameter which acts upon the particule size, which, in its turn, determine the Coulombian energy U on the site, or via the fluctuations of the inter-nano-objects spacing which determines the tunneling conductance G. That is where the magnetic field permits a continuous variation of the insulating behaviour of these self-organized networks, thus beeing model systems. Actually this domain of investigation covers two types of studies: one is devoted to the charge transport mechanisms in self-organized arrays of Multi-Walled Carbon Nanotubes (MWCNT) in presence of high magnetic field, the second type is devoted to the high magnetic field properties of low-dimensional arrays of Tin-dioxyde nanoclusters.
Members of the Laboratory involved in this activity: Jean Galibert, Taras Dauzhenka, Géraldine Ballon-Gauran
V.K. Ksenevich (Lab. Physics of Electronic Materials, Belarus State University, Minsk, Belarus)
I.A. Bashmakov (Research Institute for Physical and Chemical Problems, Belarus State University, Minsk, Belarus)
V.A. Samuilov ( Garcia Center for Polymers at Engineered Interface, Stony Brook University N. Y.
D.Seliuta (Semiconductors Physics Institute, Vilnius, Lithuania)
A.A. Melnikov (Dept Physics & Astronomy Bochum, Ruhr Universität Bochum, Germany)
Some recent publications:
Vitaly Ksenevich, Taras Dauzhenka, Dalius Seliuta, Irmantas Kasalynas, Tomas Kivaras, Gintaras Valusis, Jean Galibert, Robin Helburn, Qi Lu, Vladimir Samuilov Electrical transport in carbon nanotubes coatings of silica fibers accepted for 15th Semiconducting and Insulating Materials Conference (SIMC XV) June 15-19, 2009, Vilnius, Lithuania to be published in Physica Status Solidi
Ksenevich-VK; Odzaev-VB; Martunas-Z; Seliuta-D; Valusis-G; Galibert-J; Melnikov-AA; Wieck-AD; Novitski-D; Kozlov-ME; Samuilov-VA Localization and nonlinear transport in single walled carbon nanotube fibers J Appl. Physics 104, 73724 (2008) link: http://scitation.aip.org/getabs/ser...
Ksenevich-VK; Seliuta-D; Martunas-Z; Kasalynas-I; Valusis-G; Galibert-J; Kozlov-ME; Samuilov-VA Charge carrier transport properties in single-walled carbon nanotube fibers Proc. 13th Int. Symp. on Ultrafast phenomena in Semiconductors, Vilnius, Lithuania 2007 in Acta Physica Polonica A, 113, 1039 (2008) link: http://przyrbwn.icm.edu.pl/APP/SPIS...
Unlike the case of individual nano-objects, in theses arrays the intertubes barriers and defects play an essential role in the electrical transport properties of the carbon nanotubes arrays. Therefore, different charge transport mechanisms can be observed in the arrays of nanotubes: metallic conductivity, variable range hopping(VRH), weak localization (WL), fluctuation induced tunneling, and furthermore, combination of various mechanisms is possible as well. In thin layers of MWCNT the (...)
The phenomenon of quantum interference in disordered conductors is well known and its effects on the electrical conductance are widely used to determine the inelastic scattering time of charge carriers and, thus, the mechanisms of inelastic scattering. Because of the prominent effects of weak localization in 2D systems, the last became an object of intensive studies. But, the reduced dimensionality and the presence of disorder lead not only to enhancement of interference effects, but also (...)