K. Alex Müller – författare

This volume contains the lectures of "Earlier and Recent Aspects of Super­ conductivity", the 18th course of the International School of Materials Science and Technology, which was held at the Ettore Majorana Centre for Scientific Culture in Erice (Sicily), Italy, July 4-16, 1989. In the wake of the discovery of high-Tc oxides many international confer­ ences have been held on the subject, mainly intended for those already working in high-Tc research. Hence, the idea evolved of organizing a school dedicated to students and young scientists entering the field of superconductivity. The intention was to give a broad perspective of the field with its eight decades of research history and thus to link existing fields of knowledge and gain con­ tinuity. The new high-Tc cuprates were integrated, both historically and by subject, into the field of classical superconductivity, as well as into its newer branches of heavy-fermion, organic and chalcogenide superconductors. Even the organizers and the lecturers were surprised how many cross-links became apparent between the different branches of superconductivity. The lectures have been grouped into four parts, namely: - Fundamental properties of superconductors - Coherence-length-related properties - Electronic and magnetic properties - Theoretical models The number of applications from potential participants greatly exceeded the capacity of the facilities available. Ultimately, 100 students from 25 coun­ tries were selected to attend the course. The remarkable surroundings of the medieval town of Erice promoted a most stimulating but nevertheless relaxed atmosphere.

Structural Phase Transitions II, like its predecessor (Topics in Current Physics, Vol. 23), presents selected methods and recent advances in the experimental investigation of phase transitions in solids. The two chapters in this volume deal with electron paramagnetic resonance (EPR), and with nuclear magnetic and nuclear quadrupole resonance (NMR-NQR). Both techniques are particularly sensitive to local properties. The chapter on EPR concentrates largely on the investigation of static properties, including mean-field behaviour, critical and multicritical phenomena, whilst NMR is shown to be a powerful tool for studying nonlinear dynamics, incommensurate transitions, and disordered systems. This book will serve as an excellent introduction to the methodology and applications of EPR and NMR-NQR for all those wishing to become acquainted with these important tools for studying structural phase transitions.

Structural Phase Transitions II, like its predecessor (Topics in Current Physics, Vol. 23), presents selected methods and recent advances in the experimental investigation of phase transitions in solids. The two chapters in this volume deal with electron paramagnetic resonance (EPR), and with nuclear magnetic and nuclear quadrupole resonance (NMR-NQR). Both techniques are particularly sensitive to local properties. The chapter on EPR concentrates largely on the investigation of static properties, including mean-field behaviour, critical and multicritical phenomena, whilst NMR is shown to be a powerful tool for studying nonlinear dynamics, incommensurate transitions, and disordered systems. This book will serve as an excellent introduction to the methodology and applications of EPR and NMR-NQR for all those wishing to become acquainted with these important tools for studying structural phase transitions.

The main objective of this workshop was to review and discuss the electronic and chemical properties of layered cuprate superconductors. These are doped antiferromagnetic (AFM) insulators, and there is the possibility of a dynamic phase separation into metallic clusters and AFM areas. A clarification on the existence and the mechanism of such a phase separation is believed to be crucial for the understanding of high-Tc superconductivity in cuprates.On the one hand, theoretical and recent experimental indications in favor of this possibility were presented, on the other hand experimental papers expressing more skeptical views were also delivered. Related work on phase separations of chemical and structural origin was also included, followed by contributions on the question; “If phase separation is present, what is the pairing mechanism in the metallic clusters?”.

“This collection of reprints allows the reader to chart the course of Müller's scientific development, from his early papers in the late 1950s all the way to high-temperature superconductivity in 1985 … A particular highlight is Müller's work on the Jahn-Teller effect … written in 1967 and appearing only as an article in a conference proceedings is a gem. Other treasures include the reviews on structural phase transitions (from 1981 and 1991, respectively) that are otherwise only obtainable in specialist books.”Contemporary PhysicsIn this book some 50 papers published by K A Müller as author or co-author over several decades, amplified by more recent work mainly by T W Kool with collaborators, are reproduced. The main subject is Electron Paramagnetic Resonance (EPR) applied to the study of perovskites and other oxides with related subjects. This wealth of papers is organized into eleven chapters, each with an introductory text written in the light of current understanding. The contributions of the first editor on structural phase transitions have been immense, and because K A Müller and J C Fayet have published a review paper on the subject, the latter is reproduced in chapter VII. Not related to EPR is a part of chapter VIII on the dipolar and quantum paraelectric behavior with dielectric studies. In chapter X two papers proving the existence of Fermi glasses are reproduced.The year 1986 bears some significance: early in this year the paper by Bednorz and Müller on the possible observation of superconductivity was published. This resulted in a substantial shift in the paradigm of condensed matter physics, to which the present first editor has contributed scientifically with others and which will be reviewed in a second volume.