High Pressure Silicates And Oxides

This book presents a summary of high-pressure phase transitions of minerals and related inorganic compounds. The first part reviews the methods to investigate phase transitions by direct high-pressure and high-temperature experiments together with thermodynamic approaches that consist of calorimetric measurements and thermodynamic calculation. In the second part, phase relations and thermodynamic properties of olivine, pyroxene, garnet, spinel, perovskite, rutile, and related inorganic compounds with A2BO4, ABO3, AB2O4, and AO2 stoichiometries are described. Particular emphasis is placed on spinel- and perovskite-structured phases and their high-pressure polymorphs called post-spinel and post-perovskite phases. The last part of the book focuses on phase relations of mantle rocks and on natural high-pressure minerals from the Earth’s deep mantle and in shocked meteorites.

The vast experimental data on phase relationships in elements, oxides and silicates at high temperatures and pressures is collected in this volume together with an explanation of the basic principles governing these processes.

During the last thirty years profound developments in expe- rimental techniques to measure high temperature and pressu- res and thermodynamic properties of minerals have occurred. This technical development has been matched by an increased sophistication in applying theoretical methods to obtain new data or improve the quality of existing data. Using these newtechniques, Assessed Thermodynamic Data on Oxides and Silicates represents the successful attempt of the authors to develop an internally systematized data base which satis- fies the constraints of calorimetric measurements, phase equilibrium data, measured thermophysical properties of a phase, and heat capacities and entropies estimated from lat- tice vibrational models.

In many respects, the science of materials has only fully utilized two of its three fundamental tools - the variables of temperature and chemical composition. Pressure, the third fundamental variable altering materials, is in many ways the most remarkable, as it spans some 60 orders of magnitude in the universe. High-pressure science has experienced tremendous growth, particularly in the last few years. With recent developments in static and dynamic compression techniques, extreme pressure and temperature conditions can now be produced and carefully controlled over a wide range. Moreover, a new generation of analytical probes, many based on third-generation synchrotron radiation sources, have been developed and can now be applied for accurate determination of the structural, dynamical, and electronic properties of matter under extreme conditions. Finally, developments in computational techniques and advances in fundamental theory tested against bountiful new experimental results are both deepening our understanding of materials as a whole and guiding subsequent experimental work with new predictions. It was for this reason that this course on high-pressure science was held at the International School of Physics "Enrico Fermi" School in July 2001. Though presented in a physics forum, the title “High-Pressure Phenomena” was chosen to reflect the broad scope of the field and the diversity of recent findings. Indeed, the field spans fundamental physics and chemistry, materials science and technology, the geosciences, planetary science and astrophysics, as well as biology. The highly interdisciplinary character of the field was central to the organization of the school, though the sheer breadth of the field meant that many topics could be treated in only a cursory fashion while others were examined more in depth. The aim of the school was to present the state-of-the-art in techniques used in modern high-pressure research, highlighting those topics where applications of these techniques are currently having a major impact.

Volume 41 of Reviews in Mineralogy and Geochemistry introduces to the field of high-temperature and high-pressure crystal chemistry, both as a guide to the dramatically improved techniques and as a summary of the voluminous crystal chemical literature on minerals at high temperature and pressure. The three parts of the book introduces crystal chemical considerations of special relevance to non-ambient crystallographic studies, reviews the temperature- and pressure-variation of structures in major mineral groups and presents experimental techniques for high-temperature and high-pressure studies of single crystals and polycrystalline samples as well as special considerations relating to diffractometry on samples at non-ambient conditions.

The ever-increasing importance of chemical reactions at high and superhigh temperatures in crystalline, amorphous, and semicrystalline SOlids, as well as the reactions of these solids with gases, prompted the authors of this book to examine critically the literature available in this field and to present a general review of the subject. In this monograph we discuss those chemical and physicochemical points which we consider to be most important for solving a series of problems in the preparation and use of new inorganic materials. We hope that this book will be of interest to the many specialists working on inorganic materials. N. A. Toropov PREFACE Modem technology demands ever more materials with high mechanical strength, heat and chemical re sistance, fire resistance, special electrical properties, particular behavior toward active radiations, etc. The search for such materials requires the study of various chemical compounds, metallic alloys, and other fused in organic systems, especially oxide systems. Materials based on oxides begin to assume increasing importance in many fields of the new technology. In this connection the investigation of oxides and systems consisting of two and more oxides is expanding greatly.

High-pressure mineral physics is a field that is strongly driven by the development of new technology. Fifty years ago, when experimentally achievable pressures were limited to just 25 GPa, little was know about the mineralogy of the Earth's lower mantle. Silicate perovskite, the likely dominant mineral of the deep Earth, was identified only when the high-pressure techniques broke the pressure barrier of 25 GPa in 1970s. However, as the maximum achievable pressure reached beyond one Megabar (100 GPa) and even to the pressure of Earth’s core on minute samples, new discoveries increasingly were fostered by the development of new analytical techniques and improvements in sensitivity and precision of existing techniques. The book consists of six sections which group the papers according to their main topics: a) Elastic and Anelastic Properties; b) Rheology; c) Melt and Glass Properties; d) Structural and Magnetic Properties; e) Diffraction and Spectroscopy; f) Pressure Calibration and Generation. As many papers cover multiple topics, readers may find papers of interest in different sections. All papers are prepared with emphasis on technical details suitable for a technical reference. Many on-line software resources are also listed in as detailed a manner as possible. However, the URL of the software sites may be subject to change without notice. * State of the art in a very important branch of geophysics, namely the experimental determination of material behavior at the extreme conditions of planetary interiors * Emphasis on technical details suitable for a technical reference * Includes many on-line software resources