Strategies for tailoring new superconducting systems

Three different strategies for tailoring new superconducting systems and optimizing existing ones are reviewed. The first is based on band structure calculations and the use of empirical criteria as suggested by LF Mattheiss for evaluating the capability of new materials to host superconductivity. BaBiO3 is illustrated as an example. The second is based on high resolution electron microscopy studies and deals with finding defects in existing systems, which could lead to new structural arrangements. The discovery of Hg2Ba2(Y,Ca)Cu2O8-x is illustrated. The third strategy is based on the pressure effect on Tc. This strategy implies that the subsequent structural studies indicate the substitutions which might simulate the pressure effect. This strategy has been successful only for the La2CuO4 system. (author)