The donors of all known oneor two-dimensional organic superconductors are based on a core organic molecule that is either tetrathiafulvalene (denoted as TTF) or tetraselenafulvalene (denoted as TSeF) or some mixture of these two molecules. Coupling X, with appropriate acceptors, Y, leads to superconductivity. The oxidized form of X may be X + or X2 + species in the crystal. From ab initio quant...

The coexistence of superconductivity and ferromagnetism in 1212-RuSr GdCu O is unique among high-T materials. Samples of 2 2 8 c Ru M Sr GdCu O , with M5Ti, V and Nb; and 0#x#1, were prepared to elucidate the role of the RuO planes in this interesting 1 2 x x 2 2 8 2 layered 1212 cuprate. The solubility ranges of M5Ti and V are limited to x,0.15 whereas that of Nb extends to full substitution. ...

We investigated a series of nickel-based oxyarsenides LnNiAsO (Ln=La, Ce, Pr, Nd, Sm) compounds. CeNiAsO undergoes two successive anti-ferromagnetic transitions at TN1=9.3 K and TN2=7.3 K; SmNiAsO becomes an anti-ferromagnet below TN≃3.5 K; NdNiAsO keeps paramagnetic down to 2 K but orders anti-ferromagnetically below TN≃1.3 K. Superconductivity was observed only in Kramers non-magnetic LaNiAsO...

We present electrical and thermal specific heat measurements that show superconductivity in double-wall carbon nanotube (DWCNT) bundles. Clear evidence, comprising a resistance drop as a function of temperature, magnetoresistance and differential resistance signature of the supercurrent, suggest an intrinsic superconducting transition below 6.8 K for one particular sample. Additional electrical...

We determine the magnetic-field dependence of the pseudogap closing temperature T* within a precursor superconductivity scenario. Detailed calculations with an anisotropic lattice model with d-wave superconductivity account for a recently determined experimental relation in BSCCO between the pseudogap closing field and the pseudogap temperature at zero field, as well as for the weak initial dep...

Abstract. Using the numerical unrestricted Hartree-Fock approach, we study the ground state of a twoorbital model describing newly discovered FeAs-based superconductors. We observe the competition of a (0, π) mode spin-density wave and the superconductivity as the doping concentration changes. There might be a small region in the electron-doping side where the magnetism and superconductivity co...

The recently discovered ruthenocuprates have attracted great interest because of the microscopic coexistence of superconducting and ferromagnetic order. Typically, these materials become magnetically ordered at temperatures around 125-145K and superconductivity sets in between 15 and 50K. While superconductivity arises in the CuO2 layers the RuO2 layers in between order magnetically. In this pa...

We have studied the field at which superconductivity nucleates in grain-aligned samples of Y1Ba2Cu3O7-δ very close to the transition temperature Tc. For the field parallel to the c axis and for temperatures within 2 K of Tc, the nucleation field is found to vary as (1-T/Tc)1/2. The data suggest that superconductivity localized near twin boundaries may exist at temperatures close to Tc. .AE

Co-doping of lanthanum and phosphorus in CaFe₂As₂ induces superconductivity at 45 K. This superconducting transition temperature is higher than the 38 K transition in Ba₁-xKxFe₂As₂, which is the maximum found thus far among the 122 phases. Superconductivity with a substantial shielding volume fraction was observed at 0.12 ≤ x ≤ 0.18 and y = 0.06 in Ca₁-xLaxFe₂(As₁-yPy)₂. The superconducting pha...

At present an algebra of strongly interacting fields is unknown. In this paper it is assumed that the operators of strongly nonlinear field can form a non-associative algebra. It is shown that such algebra can be described as an algebra of some pairs. The comparison of presented techniques with the Green’s functions method in the superconductivity theory is made. A possible application to the Q...