26 research outputs found
Organic Superconductors: when correlations and magnetism walk in
This survey provides a brief account for the start of organic
superconductivity motivated by the quest for high Tc superconductors and its
development since the eighties'. Besides superconductivity found in 1D organics
in 1980, progresses in this field of research have contributed to better
understand the physics of low dimensional conductors highlighted by the wealth
of new remarkable properties. Correlations conspire to govern the low
temperature properties of the metallic phase. The contribution of
antiferromagnetic fluctuations to the interchain Cooper pairing proposed by the
theory is borne out by experimental investigations and supports
supercondutivity emerging from a non Fermi liquid background. Quasi one
dimensional organic superconductors can therefore be considered as simple
prototype systems for the more complex high Tc materials.Comment: 41 pages, 21 figures to be published in Journal of Superconductivity
and Novel Magnetis
STRUCTURES CRISTALLINES DE PRODUITS DONNANT UNE PHASE NÉMATIQUE A LA FUSION
Les structures cristallines de deux composés donnant une phase nématique à la fusion ont été déterminées à partir des données de diffraction de Rayons X par des monocristaux. Il s'agit de l'anisaldazine : CH3-O-C6H4-CH = N-N = CH-C6H4-O-CH3 et du 4-4' azodiphénétole : C2H5-O-C6H4-N = N-C6H4-O-C2H5. Bien que ces deux produits cristallisent dans des groupes de symétrie différents, l'empilement des molécules est assez semblable et montre que les interactions dipôle-dipôle existent à l'état cristallisé.The crystal structures of two nematogenic compounds have been determined from X-Ray diffraction data collected with a single crystal diffractometer. These two compounds are : Anisaldazine CH3-O-C6H4-CH = N-N = CH-C6H4-O-CH3 and 4-4' azodiphenetole C2H5-O-C6H4-N = N-C6H4-O-C2H5. Though they cristallize in two different space groups, the packing of molecules is similar and show that interactions dipole-dipole exist in crystalline state
Programmes pour calculs cristallographiques réalisés sur calculateur électronique I. B. M. 1620
Falgueirettes Jean, Galigné Jean-Louis, Lapasset Jacques. Programmes pour calculs cristallographiques réalisés sur calculateur électronique I. B. M. 1620. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 87, 1, 1964. pp. 90-93