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991.
Measurement of alternating current conductance in the gigahertz regime of free standing nitrogen incorporated nano-diamond films is reported. Using a simple and newly developed technique, the scattering parameters of the nanodiamond films were measured on coplanar waveguides. The conductance is evident as a crossover from insulating behaviour where to the metallic regime where . From the micro-Raman studies of the films we conclude that this crossover is due to the changes in the grain boundary morphology which is driven by the level of nitrogen during synthesis. These results are in agreement with previous direct current measurements.https://doi.org/10.1209/0295-5075/109/67002 相似文献
992.
Marie Paule Pileni 《Europhysics letters》2015,109(5)
Here it is shown that the chemical and physical properties of a collection of nanocrystals either isolated or self-assembled in 3D superlattices called supracrystals markedly depend on the crystalline structure of the nanocrystal.https://doi.org/10.1209/0295-5075/109/58001 相似文献
993.
994.
A. Yassar;H. Jaafari;N. Rebière-Galy;M. Frigoli;C. Moustrou;A. Samat;R. Guglielmetti 《欧洲物理学杂志; 应用物理学》2002,18(1):3-8
We present a new approach for the realisation of a molecular photo-switch, based on photochrochromic oligothiophene-substituted chromenes. When optically excited, these compounds undergo a structural change passing from a neutral state (closed form) to a strongly polarized one (open form). This photochromic process is accompanied by a deep changes in the electrical characterisation. https://doi.org/10.1051/epjap:2002020 相似文献
995.
996.
S. Spadoni;L. Colombo;P. Milani;G. Benedek 《Europhysics letters》1997,39(3):269-274
We investigated by tight-binding molecular dynamics the coalescence of fullerenic fragmentsand carbon clusters by following the evolution of the topological connectivity. Thoughdifferent temperature variation protocols lead to irregular structures, their connectivity isfound to stabilize at values corresponding either to three-branched schwarzites or tubulenes,indicating that long-time evolution at constant connectivity is potentially able toyield regular shapes. These results can be related to experiments on laser-induced transformationsof fullerite occasionally yielding branched structures with a schwarzite shape.https://doi.org/10.1209/epl/i1997-00346-7 相似文献
997.
I. Alibert;C. Coulon;A. M. Bellocq;T. Gulik-Krzywicki 《Europhysics letters》1997,39(5):563-568
We discuss in this letter the dilute part of the phase diagram of thepseudo-ternary system (brine + glycerol), SDS, hexanol through FreezeFracture Electron Microscopy (FFEM) and dielectric measurements. Themain conclusion is the observation of a large one-phase domain L* instead of an L4 phase as usually found in similar systems. ThisL* domain is connected to the sponge domain, through pathssurrounding the lamellar phase. We show by FFEM that samples in theL* domain are mostly composed of vesicles. However, they present adielectric behavior different from a vesicle phase. We conclude thatL* is not a vesicle phase but is a sponge phase whose topology isdifferent from the one found in the concentrated part of the L3 phase(see Gazeau D., Bellocq A. M., Roux D. and Zemb T. , Europhys. Lett. , 9 (1989) 447 andPorte G., Marignan J., Bassereau P. and May R. J. Phys. (Paris) , 49 (1988) 511). These results bring new light on thesponge stability. https://doi.org/10.1209/epl/i1997-00395-x 相似文献
998.
J. C. Pivin;G. Rizza;F. Garrido;L. Thomé 《Europhysics letters》1997,39(6):623-626
The mixing mechanism of thin layers of Au, Pt or W embedded in silica when irradiated with 4.5MeV Au ions was studied as a function of the ion fluence ϕ , temperature T and layer thickness d . Analysis of the diffusion process by means of Rutherford backscattering spectrometry showed that the spreading of metal peaks was anisotropic and that their variance varied as ϕ at room temperature or at 100K. This behavior is attributed to an association of metal atoms with diffusing defects.https://doi.org/10.1209/epl/i1997-00404-8 相似文献
999.
Y. Imry;A. Stern;U. Sivan 《Europhysics letters》1997,39(6):639-644
The temperature dependence of the conductivity of a granular system is considered in a regime whereelectronic transport is facilitated by inelastic electron-electron scattering. We analyze thetemperature dependence of the electron-electron scattering rate of the system, and find that itleads, for a wide temperature range, to a linear dependence of the conductivity on T .https://doi.org/10.1209/epl/i1997-00407-y 相似文献
1000.
L. F. Rybaltchenko;I. K. Yanson;A. G. M. Jansen;P. Mandal;P. Wyder;C. V. Tomy;D. McK. Paul 《Europhysics letters》1996,33(6):483-488
Andreev-reflection spectra of superconducting-normal contacts with show a continuous increase of the superconducting order parameter at the antiferromagnetic phase transition K without re-entrant behaviour below the superconducting critical temperature K. A change is found in the superconducting ground state at K (zero magnetic field), and the magnetic-field–temperature phase diagram corresponding to the two superconducting states is reconstructed. https://doi.org/10.1209/epl/i1996-00367-8 相似文献