The atomic dynamics in liquids is still a challenging subject. The objective of this thesis was to study how the dynamics depends on the TYPE of the atomic interaction. Dynamic properties extracted from inelastic neutron scattering experiments on three binary systems clearly show a discontinous behaviour in the transition from a pure metallic to an ionic and partly covalent bonding regime. Further, results of Monte-Carlo simulations of a new type of spectrometer, a Neutron-Brillouin-Spectrometer, that is currently under construction, are presented.

This ASI was planned to make a major contribution to the teaching of the principles and methods used in liquid phase ~esearch and to encourage the setting up of collaborative projects, as advocated by the European Molecular Liquids Group (secretary: Dr J. Yarwood, University of Durham, U. K. ). During the past five years considerable progress has been made in studying molecular liquids. The undoubted advantages of international collaboration led to the formation of the European Molecular Liquids Group (EMLG) in July 1981. The activities of the EMLG were widely disseminated in a special session of the European Congress on Molecular Spectroscopy (EUCMOS) held in September 1981 (for details, see J. Mol. Structure, 80 (1982) 375 - 421). Following the success of this meeting, it was thought that the aims and objectives of the E~G would be best served by the organisation of a broader-based gathering designed to attract those interested in the study of the structure, dynamics and interactions in the liquid state. Thanks to the generous support by the Scientific Affairs Division of NATO, it was possible to hold a NATO ASI on Molecular Liquids at the Italian Centre of Stanford University, Florence, Italy during June-July 1983. This book is based on the lectures presented at that meeting. The contents of this volume cover the three broad areas of current liquid phase research: (a) Analytical theory.

Many macroscopic properties of materials are determined primarily by inhomogeneous structures and textures. These intermediate-scale structures often arise from competing interactions operating on different length scales within the material. Our understanding of such phenomena has increased substantially with the identification and theoretical description of solid-state materials with incommensurate and long-period modulated phases, such as ferroelectrics, charge-density-wave compounds, epitaxial layers and polytypes. Experimental diagnosis of inhomogeneous ground states and metastable phases has advanced so far that these are now well-accepted phenomena. These proceedings bring together the work of physicists and materials scientists to review developments in this area and to examine possible future directions, such as how the microscopic understanding emerging in bench-top solid-state systems can be applied in materials science.

Systems displaying competing interactions of some kind are widespread - much more, in fact, as commonly anticipated (magnetic and Ising-type interactions or the dynamics of DNA molecules being only two popular examples). Written for researchers in the field with different professional backgrounds, this volume classifies phenomena not by system but rather by the type of competing interactions involved. This allows for a straightforward presentation of the underlying principles and the universal laws governing the behaviour of different systems. Starting with a historical overview, the author proceeds by describing self-competitions of various types of interactions (such as diploar or multipolar interactions), competitions between a short-range and a long-range interaction (as in Ising systems or DNA models) or between a long-range interaction and an anisotropy (as in ultrathin magnetic films or magnetic nanoparticles) and finally competitions between interactions of the same range (as in spin glasses). Each chapter contains a few problems with solutions which provide suitable material for lecturers of mathematics and physics as well as biology courses. A vast body of references to the original literature make the volume self-contained and ideally suited to master this interdisciplinary field.