Borocarbides superconductivity

Superconductivity has also been discovered in rather exotic materials, including the following Buckminsterfullerene (Cgo) doped with ICI Carbon nanotubes (superconductivity in just one direction) Nickel borocarbides, which contain Ni2 B2 layers alternating with R C sheets, where R is a rare earth element such as Er and organic superconductors that contain planar organic cations and oxoanions. Chemists and physicists continue to study these and other families of superconductors. 

MAGNETIC AND SUPERCONDUCTING PROPERTIES OF RARE EARTH BOROCARBIDES OF THE TYPE / Ni2B2C... 

Borocarbide superconductors with LuNi2B2C-type structure and their superconducting transition temperature Tc... 

Fig. 12. Tetragonal rare-earth nickel borocarbides (nitrides) with (a) single, (b) double and (c) triple t C(N)-Layers and values of the superconducting transition temperature Tc (Cava et al. 1994c Gao et al. 1994 ...

The investigation of the whole family of these multilayer compounds would help to understand the mechanisms for superconductivity and magnetism in the quaternary rare-earth transition-metal borocarbides (Michor et al. 2001 Baggio-Saitovitch et al. 2001). However this report will be confined to magnetism and superconductivity in singlelayer / Ni2B2C compounds i.e. compounds with (/ C/N) Ni2B2 with n > 1 will not be considered further. 

Based on ac magnetic susceptibility and specific heat measurements, El Massalami et al. (1998a) claimed that they observed superconductivity in CeNi2B2C with Tc of about 0.1 K. If this will be confirmed the mechanisms for superconductivity in the whole borocarbide series should be reconsidered. 

Alleno, E P. Berger, E. Leroy and C. Godart, 2001, in Rare Earth Transition Metal Borocarbides (Nitrides) Superconducting, Magnetic and Normal State Properties, eds K.-H. Muller and V.N. Narozh-nyi (Kluwer Acad. Publ., Dordrecht) p. 265. 

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