Reentrant superconducting

Sushko YV, Ito H, Ishiguro T, Horiuchi S, Saito G (1993) Reentrant superconductivity in k-(BEDT-TTF)2Cu[N(CN)2]C1 and its pressure phase diagram. Solid State Commun 87 997-1000... 

Fig. 5. Reentrant superconductivity in NdojsThg 65RU2 (after Hiiser et al. 1983). Upon cooling, first, the real part of the ac susceptibility, x. becomes negative, indicating superconductivity. Then the material reenters the normal state (x > 0) and reentrance of superconductivity occurs at lower temperatures.

Fig. 6. Resistance-vs.-temperature curves of a GdMO(,Sg sample for different values of the applied magnetic field, indicating near-reentrant superconductivity i.e. reentrant behaviour at finite field only (nominal composition...

Reentrant superconductivity is known from so-called ferromagnetic superconductors like ErRh4B4 where the ferromagnetic transition at lower temperatures actually destroys superconductivity [244]. However, the exact magnetic structure in k-(ET)2Cu[N(CN)2]C1 is still unknown and the origin of the peculiar behavior is at present subject of speculations only. 

Oscillations in the transition temperature of SF sandwiches as a function of F-layer thickness, <7f, including reentrant superconductivity [10, 11]. 

Reentrant superconductivity was first discovered with ErRh4B4. [204] The chain of trans edge condensed M4 tetrahedra in which the coordinating atoms lie above all faces of the tetrahedra has been called a Tfetraederstern by Schubert. This very common feature links the structural chemistry of condensed cluster compounds with that of the intermetallic phases. [205]... 

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