Impact of Crystal Chemistry upon the Physics of Strongly Correlated Electrons in Oxides

摘要

The numerous studies that were performed these last twenty five years on strongly correlated electrons in oxides have shown that they represent a great potential for applications as functional materials. This is the case of high critical temperature (T_c) superconducting cuprates which are of high interest in electronic applications, but also in high-current applications for saving energy, and as magnetic bearings. Similarly, oxides have been investigated for their potential as magnetic memory materials and actuators, as for example in the studies of colossal magnetoresistance manganates, and of many other oxides, called multiferroics which combine both ferroelec-tricity and ferromagnetism. A third example is given by the thermoelectric cobaltates, which exhibit good performances at high temperature and offer a possible solution for saving energy by conversion of waste heat into electricity. In fact, transition-metal oxides were considered for a long time as inadequate materials for investigation by physicists, owing to their too complex crystal chemistry.