Layer lattice compounds superconductivity

The second difference between the nickel and copper compounds is that La2Cu04 is a superconductor, being the first of the Cu02 layer compounds in which superconductivity was observed. The lattice-induced strain is a necessary condition for superconductivity since it stabilizes the higher oxidation state needed to provide the superconducting carriers as discussed in Section 13.3.2. 

ZrNCl Co(Cp)2 o,io has been shown to be a Type II superconductor with a superconducting transition at 14 K. This is the highest for any metallocene intercalation compound. The superconducting transition temperatures for all three metallocene intercalation compounds are the same as those in the alkali metals intercalates with the same doping level reported by Yamanaka et The transition temperature appears not to be dependent on the interlayer separation and on the doping level which suggests that the superconductivity is largely confined to the thin two-dimensional ZrN layers of the host lattice. 

The crystal structure of high (90 K) superconducting cuprates is based on a perovskite lattice with an orthorohonibic distortion [124] (Figure 5.28). In the various families of the.se compounds, copper ions exhibit various coordinations four planar-square, five pyramidal, six octahedral. In all cases the four bonds in the perovskite layers are shorter that the Cu-0 bonds between layers. 

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