Equations of State for Solids at High Pressures and Temperatures

Abstract

All riehts reservPrlNo part of this publication may be reproduced in any form without written permission from the publisher PREFACE TO THE AMERICAN EDITIONWe started our work on theoretical methods in the phys ics of high pressures (in connection with geophysical applications) in 1956, and we immediately encountered many problems. Naturally, we searched the published Iiterature for solutions to these problems but whenever we failed to find a solution or when the solution did not satisfy us, we attempted to solve the problern ourselves. We realized that other investigators working in the physics of high pressures would probably encounter the same problems and doubts. Therefore, we decided to write this book in order to save our colleagues time and effort. Apart from the descriptions of experimental methods, the book deals only with those problems which we encountered in our own work.Allproblems in high-pressure physics have, at present, only approximate solutions, which are very rough. Therefore, it is not surprising that different investigators approach the same problems in different ways. Our approach does not prejudge the issue and we are fully aware that there are other points of view. Our aim was always to solve a glven problern on a physical basis. For example, the concept of the Grüneisenparameter needs further development but it is based on reliable physical ideas. On the other hand, Simon's equation for the melting curve has, in our opinion, no clear physical basis and is purely empirical. Equations of this type are useful in systematic presentation of the experimental material but they are unsuitable for any major extrapolation.A couple of years have passed since the manuscript of this book was sent to press. Since then, additional experimental data have become available. A high proportion of these data can be analyzed by the methods described in the present book. However, their incorporation would not improve the book very greatly. One of the most pressing needs in high-pressure physics is to improve the accuracy of the measurements. When this barrier is surmounted, we shall then see which methods for the analysis of the experimental data should be refined and which should be replaced.We are pleased to hear that our book will be published in the home country of P. W. Bridgman, and we are grateful to Plenum Publishing Corporation for arranging the translation. Moscow, November 1969 V V. N. Zharkov V. A. Kalinin PREFACEThe theoretical methods used in the high-pressure physics of solids are the subject of the present book. The development of these methods has been stimulated primarily by geophysics problems to which such methods have been applied in the first instance. Special attention is paid in the book to the equation of state, i.e., to the dependence of the pressure P on the volume V and the temperature T.The equation of state is the basic relationship in high-pressure physics. It contains valuable information on the properties of a medium and it allows us to carry out transformations from one thermod...

Theoretical modeling of molar volume and thermal expansion

“…Three well-known approximations used to account for the Grüneisen parameter γ can be combined into the following expression (Zharkov and Kalinin, 1971;Wasserman et al, 1996),…”

Experimental study of the bcc-fcc phase transformations in the Fe-rich system Fe-Si at high pressures

“…Согласно работам [Zharkov, Kalinin, 1971;Burakovsky, Preston, 2004;и др. ], зависимость параметра Грюнейзена от объема на нулевой изотерме можно записать в виде:…”

Ab initio theory of planetary materials

“…Rather, he suggested that at high pressure GPa in the core) silicates of Mg, Al, and Ca are transformed into ultradense metallic forms. This idea is geochemically not viable, and was not suported by experiments (see [128]) or theoretical calculations (see, e.g., [129]): mantle silicates and oxides remain insulating and never adopt superdense structures or become metallic at the Earth's core conditions. For example, Oganov et al [24] predicted metallization of MgO at the pressure of 21 TPa (in the CsCl-type structure), more than 50 times higher than the pressure at the centre of the Earth.…”