PROCEEDINGS OF THE INTERNATIONAL SCHOOL OF PHYSICS "ENRICO FERMI"_1 pptx

SOCIETA ITALIANA DI FISICA RENDICONTI DELLA SCUOLA INTERNAZIONALE DI FISICA "ENRICO FERMI" CXLVII CORSO a cura di R J HEMLEY e G L CHIAROTTI Direttori del Corso e di M BERNASCONI e L ULIVI VARENNA SUL LAGO DI COMO VILLA MONASTERO – 13 Luglio 2001 Fenomeni ad alte pressioni 2002 SOCIETA ITALIANA DI FISICA BOLOGNA-ITALY ITALIAN PHYSICAL SOCIETY PROCEEDINGS OF THE INTERNATIONAL SCHOOL OF PHYSICS "ENRICO FERMI" COURSE CXLVII edited by R J HEMLEY and G L CHIAROTTI Directors of the Course and by M BERNASCONI and L ULIVI VARENNA ON COMO LAKE VILLA MONASTERO – 13 July 2001 High Pressure Phenomena 2002 Ohmsha AMSTERDAM, OXFORD, TOKYO, WASHINGTON DC Copyright © 2002 by Societa Italiana di Fisica All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner ISBN 58603 269 (IOS Press) ISBN 274 90538 C3042 (Ohmsha) Library of Congress Catalog Card Number: 2002110641 Production Manager A OLEANDRI Copy Editor M MISSIROLI Publisher IOS PRESS Nieuwe Hemweg 6B 1013 BG Amsterdam The Netherlands fax: +31 20 688 33 55 e-mail: order@iopress.nl Distributor in the UK and Ireland IOS Press/Lavis Marketing 73 Lime Walk Headington Oxford OX3 7AD England fax: +44 1865 75 0079 Distributor in the USA and Canada IOS Press, Inc 5795-G Burke Center Parkway Burke, VA 22015 USA fax: +1 703 323 3668 e-mail: iosbooks@iospress.com Distributor in Germany, Austria and Switzerland IOS Press/LSL.de Gerichtsweg 28 D-04103 Leipzig Germany fax: +49 341 995 4255 Proprieta Letteraria Riservata Printed in Italy Distributor in Japan Ohmsha, Ltd 3-1 Kanda Nishiki-cho Chiyoda-ku, Tokio 101 Japan fax: +81 3233 2426 Supported by UNESCO VENICE OFFICE (UVO-ROSTE) Supported by Consiglio Nazionale delle Ricerche (CNR) Supported by Istituto Nazionale di Fisica Nucleare (INFN) Supported by Istituto Nazionale per la Fisica della Materia (INFM) This page intentionally left blank INDICE R J HEMLEY, G L CHIAROTTI, M BERNASCONI and L ULIVI - Preface Gruppo fotografico dei partecipanti al Corso pag XIX » XXX STATIC COMPRESSION: OVERVIEW AND TECHNIQUES R J HEMLEY and H K MAO - Overview of static high pressure science Introduction Pressure generation techniques 2.1 Evolution of very high pressure techniques 2.2 Measurement of pressure and stress 2.3 Variable temperature In situ high pressure probes 3'1 Synchrotron radiation 3.2 Polycrystalline X-ray diffraction 3.3 Single-crystal X-ray diffraction 3.4 Radial X-ray diffraction 3"5 X-ray spectroscopy and inelastic scattering 3'6 Neutron diffraction and scattering 3.7 Optical spectroscopy 3.8 Electrical and magnetic methods 3.9 Other techniques Selected applications 4.1 Dense solid hydrogen 4.2 Pressure-induced metallization and superconductivity 4.3 Polymeric nitrogen and other new materials 4.4 "Simple" silicates and oxides 4.5 Iron in the Earth's core 4.6 Pressure effects on biological systems 4.7 New generation of high pressure devices Conclusions » » » » » » » » » » » » » » » » » » » » » » » » » 6 10 11 13 13 14 15 16 16 18 18 20 20 20 20 22 24 26 27 30 30 32 VII VIII INDICE T YAGI - Experimental overview of large-volume techniques Introduction Development of large-volume apparatuses 2.1 Evolution of the piston-cylinder apparatus 2.2 The "DIA-type" apparatus 2.3 Double-stage apparatus 2.4 Use of sintered diamond Basic technique for large-volume experiments 3.1 Single-stage cubic anvil 3.2 Double-stage apparatus Combination with synchrotron radiation Pressure and temperature measurements Advantages and problems of large-volume apparatuses Current prospects for large-volume techniques Summary pag » » » » » » » » » » » » » » 41 41 41 41 43 44 45 46 46 47 49 51 52 52 53 » 55 Introduction The laser-heated diamond cell Melting experiments and phase diagrams Alkali halides Aluminum Transition metals Alkaline-earth metals Rare-earth metals Noble gases » » » » » » » » » 55 56 59 61 62 62 65 65 68 J S LOVEDAY - Crystallography at high pressure » 73 Introduction Radiation Data collection—powder diffraction 3'1 X-ray powder diffraction 3'2 Neutron powder diffraction 3'3 Powder diffraction concluding remarks Single-crystal diffraction Data collection—concluding remarks Analysis Further sources of information Conclusions » » » » » » » » » » » 73 73 74 75 77 79 79 81 81 83 83 » 87 » » 87 88 R BOEHLER, D ERRANDONEA and M Ross - The laser-heated diamond cell: High P-T phase diagrams Y K VOHRA and S T WEIR - Designer diamond anvils in high pressure research: Recent results and future opportunities Introduction 1.l Advent of designer diamond technology IX INDICE Experimental 2.1 Chemical vapor deposited diamond 2.2 Optical lithography of electrical microprobes and micro-loops Designer diamond anvils—recent experimental results 3.1 Insulator to metal transition in potassium iodide studied using designer diamond anvils 3.2 Four-probe electrical resistance measurements on fullerene C70 using designer diamond anvils 3.3 Four-probe electrical resistance measurements on single wall carbon nanotubes samples using designer diamond anvils 3.4 Four-probe electrical resistance measurements on beryllium using designer diamond anvils 3'5 Magnetic susceptibility measurements with designer loop anvils Future opportunities 4.1 Next generation of designer diamond anvils: Multitasking designer diamond anvils pag » » » 89 90 91 91 » 91 » 93 » 97 » » » 100 102 104 » 104 DYNAMIC COMPRESSION: OVERVIEW AND TECHNIQUES W J NELLIS — Dynamic experiments: An overview Introduction Shock compression 2.1 Simple shock waves 2.2 Rankine-Hugoniot relations and equations of state 2.3 Thermal equations of state and static high pressure scales 2'4 Shock temperatures and optical emission spectra 2'5 Shock wave profiles 2.5.1 Elastic-plastic flow and material strength 2.5.2 Shock-induced phase transitions 2.6 Release of shock pressure by sound waves 2.6.1 Speed-of-sound measurements 2.6.2 Gruneisen parameter and phase transitions 2.7 Electrical resistivity 2.8 Raman spectroscopy 2.9 Flash X-ray diffraction 2.10 Computer simulations Synthesis and recovery of materials 3.1 Nanocrystalline materials 3.2 Films 3.3 Bond strengths between film and substrate 3.4 Shock-induced defects and flux pinning 3.5 Synthesis of hard materials 3.6 Powder consolidation 3.7 Shock-induced chemical reactions and reactivity 3.8 Shock-induced melting and rapid resolidification 3.9 Explosive systems to synthesize diamond particles 109 109 110 111 112 115 116 117 117 118 118 119 119 120 120 120 121 121 122 123 123 123 123 123 124 124 124 X INDICE V E FORTOV and V B MINTSEV — Strongly coupled plasma physics at megabar pressures Introduction Shock waves and strongly coupled plasma Generators and drivers Plasma under extreme conditions 4.1 Equation of state 4.2 Optical properties 4.3 Electrical conductivity 4.4 Adiabatic expansion Conclusions pag 127 » » » » » » » » » 127 127 129 134 134 137 139 141 144 THEORY AND FUNDAMENTALS N W ASHCROFT — Condensed matter at higher densities » 151 Introduction Nuclei and electrons: formulating the problem at variable volume Structure: the fundamentals Ions and electrons, and the role of pressure Structure and multi-center potentials Electrons in static lattices; dynamic lattices and their limits Liquids and the role of pressure Pair-correlation, the Percus argument, and liquids at high pressure Hydrogen at high pressure Near ground states of dense hydrogen Electronic instability and pairing Ground-state liquid-like phases » » » » » » » » » » » » 151 154 158 160 163 167 172 176 179 181 187 189 S SCANDOLO - First-principles molecular dynamics simulations at high pressure » 195 » » » » » » » » » » » » » » 195 197 197 197 199 201 202 203 204 204 205 205 207 207 10 11 12 Introduction Molecular dynamics 2.1 Basic concepts 2.2 Molecular dynamics at constant pressure 2.3 First-principles MD 2.4 The Car-Parrinello method 2.5 First-principles MD at constant pressure 2.6 Empirical potentials from first-principles simulations Applications 3.1 Silicon 3.2 Carbon 3.3 Hydrogen 3.4 Oxygen 3.5 Carbon oxides 340 L ULIVI the rhombohedral e-N (R3c) [39–42] are both fully ordered structures With increasing temperature, instead, the orientational ordering of the molecules is lost In /?–N2, indeed, the molecular centers are on a hexagonal close-packed (hcp) lattice, but their orientation is not fixed, and perform hindered rotations [29, 43–47] Also in 6-N (cubic, Pm3n) the eight molecules in the primitive cubic cell not have fixed orientations, and show a very peculiar arrangement The molecules on the vertices and on the center of the cube (sites of Th symmetry) have a spherical statistical distribution, while the other molecules, positioned two on each face of the cube, on sites of D2d symmetry, have a disk-like orientational distribution in a plane perpendicular to the cube face Recently, by means of Raman spectroscopy, a new phase, named £1oc, was detected [29 ,48] Infrared absorption measurements have demonstrated that the structures of the and