Publisher's Synopsis
The aim of this special issue is to collect in one place a series of articles devoted to the variety of phase transitions and complex ordering phenomena which take place prior to the onset of superconductivity. Most of the literature to date on these transitions, especially those falling between room temperature and the onset of superconductivity, has been interpreted in terms of magnetic or purely electronic mechanisms. By contrast, this special issue draws on studies such as those using dielectric, ultrasonic and microwave methods which give information on the underlying electric rather then magnetic or purely electronic properties of the phase transitions. Such dielectric, electrical ferrodistortive properties are less familiar to scientists working with conventional metallic superconductors since in that case they play a relatively minor role.;For those scientists who have devoted years of effort to the study of ferrodistortive phase transitions in perovskite oxides, including those which involve semiconductor properties (e.g. positive temperature coefficient (PTC) effect), the dielectric and electrical properties are well known to play a key role in the mechanism of the transition. This issue, by bringing to the high temperature superconductivity field a somewhat different perspective, aims to help widen our scientific understanding of this new class of superconductors.
