Quasi-Two-dimensional Charge-Transfer Systems as Superconductors

Quasi-Two-dimensional Charge-Transfer Systems as Superconductors 

The second, considerably larger group of organic superconductors has as their organic basic structural unit the donor molecule bisethylene-dithiolo-tetrathio- 

we will take the salt /3-(ET)2l3 as an example. This salt becomes superconducting even at normal pressure, with a critical temperature of Tc = 1.5 K. With a moderate applied pressure, Tc can be increased to 8 K. 

The crystal structure is shown in Fig. 10.7, and the transition from the normal to the superconducting state is illustrated in Fig. 10.8. In these salts, there are a niun-ber of somewhat different crystal structures or phases which differ in the detailed 

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