CLUSTERS superconducting materials

There also exist structural similarities between the MeN clusters and the class of solid-state compounds known as transition metal nitrides. In these refractory compounds the nitrogen exists in either an octahedral or a trigonal prismatic array of transition metals 125). The interest in using transition metal nitrides for superconducting thin films as well as chemically inert coatings (i25) should promote studies in which nitrido clusters could be used as starting materials for the synthesis of new refractory materials. 

Superconductivity. The insulator-superconductor transition takes place near this composition probably as a result of the percolation of the hole doped clusters. At x = 6.342 small amounts of the material become superconducting (fig. 27b). Superconductivity under pressure A giant ATJAP effect has been measured at RT (sect. 5.4) indicating an increased compressibility at the T-0 transition due to the half-filled chains and strong oxygen-ordering effects. The effect disappears at LT where the mobility of oxygen freezes (fig. 58). 

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