Insulator-superconducting boundary

Fig. 11 Schematic electronic phase diagram of C q compounds, showing the approximate location of the metal (superconducting)-insulator phase boundary. Open symbols are values of Tc for superconducting fullerides solid symbols indicate TN (ambient pressure) and Tc (>1 GPa) of (NH3)K3C60...

Fig. 17. Local (g-integcated) susceptibility for antiferromagnetic and superconducting Laj jtSr,Cu04. The energies over which magnetic correlations exist ate comparable for jc=0 and jc = 0.14. However, the doped sample displays a low-energy peak in the spectrum at 20-30meV which is not present in the insulator (where the spectrum is maximum at the zone-boundary energy due to the van Hove singularity in the density of states). From Hayden et al. (1998).

---