Ferroelectricity in high-Tc superconductors

Crystal structures or exposure to polarisable environments determined the superconductivity in the Y-Ba-Cu-O system. Based on the sequence of broken symmetry and lattice distortions in perovskite structures, quasi-ferroelectricity (QF) is considered to play an important role in the new superconductive oxide compounds. The authors suggest an idea for seeking higher-Tc superconductive systems.