Materials Under Extreme Conditions

Recent Trends and Future Prospects

A.K. Tyagi, S. Banerjee, A. K. Tyagi

• Publisher: Elsevier
• Year: 2017
• Print ISBN: 9780128013007
• eBook ISBN: 9780128014424
• Topic: Technology & Engineering
• Subtopic: Industrial Design
• Index: Technology & Engineering

Materials Under Extreme Conditions: Recent Trends and Future Prospects analyzes the chemical transformation and decomposition of materials exposed to extreme conditions, such as high temperature, high pressure, hostile chemical environments, high radiation fields, high vacuum, high magnetic and electric fields, wear and abrasion related to chemical bonding, special crystallographic features, and microstructures.The materials covered in this work encompass oxides, non-oxides, alloys and intermetallics, glasses, and carbon-based materials. The book is written for researchers in academia and industry, and technologists in chemical engineering, materials chemistry, chemistry, and condensed matter physics.- Describes and analyzes the chemical transformation and decomposition of a wide range of materials exposed to extreme conditions- Brings together information currently scattered across the Internet or incoherently dispersed amongst journals and proceedings- Presents chapters on phenomena, materials synthesis, and processing, characterization and properties, and applications- Written by established researchers in the field

Chapter 1

Material Studies at High Pressure

Surinder M. Sharma, and Nandini Garg Bhabha Atomic Research Centre, Mumbai, India

Abstract

Subjecting materials to very high pressures is one of the well-established methods to study condensed matter under extreme conditions. Application of pressure can bring about significant changes in the bonding character and consequently in the structural and physicochemical properties of the materials. High-pressure and high-temperature conditions can help simulate the physical conditions inside the earth, planets, and super-earth, synthesize new materials with exotic properties, etc. Even food preservation and successful preservation of organs for transplant can be carried out by application of pressure. This chapter deals with several aspects of high-pressure science, methods of pressure generation, different diagnostic methods employed for studying high-pressure phenomena, and a few studies elucidating the exciting changes in the materials brought about by its application.

Keywords

Amorphization; Diamond anvil cell; High pressure; Negative thermal expansion; Phase transitions; Raman spectroscopy; Recrystallization; X-ray diffraction

Chapter Outline

1. Introduction

2. Experimental and Theoretical Methods to Study Materials at High Pressure

2.1 Diamond Anvil Cells

2.2 Preparation of Diamond Anvil Cells for Experiments

3. Diagnostics

3.1 High-Pressure Diffraction

3.2 Hydrostatic and Nonhydrostatic Stresses and Radial X-Ray Diffraction

3.3 High-Pressure Spectroscopy and Inelastic Scattering

3.4 High-Pressure Transport Property Measurements

3.5 High-Pressure 3D Tomography

4. Some Case Studies

4.1 Mechanism of Phase Transitions Under High Pressure

4.1.1 Nanozircon-Structured Chromates

4.1.2 Alpha Cristobalite

4.1.3 Scandium Tungstate

4.2 Pressure-Induced Amorphization

4.2.1 Berlinite

4.2.2 Silicon

4.2.3 Yttrium Chromate and Holomium Chromate

4.2.4 Reduced Graphene Oxide

4.3 Negative Thermal Expansion and Amorphization

4.3.1 Scandium Tungstate

4.3.2 Ag₃[Co(CN)₆]

4.3.3 Zn(CN)₂

4.4 Recrystallization of Amorphous Phase

4.4.1 Silicon

4.5 Amorphous to Amorphous Phase Transition

4.5.1 Silicon

4.5.2 GeO₂

4.6 Dissociation Under Pressure

4.6.1 Lanthanum Hafnate

4.7 Molecular Solids

5. Future Prospects

Acknowledgments

References

1. Introduction

Pressure and temperature are two important thermodynamic variables that can bring about several changes in condensed matter. Application of pressure brings about larger changes at very low pressures compared to temperatures as the change in Gibbs free energy of elements on application of pressure is ∼10 kJ/mol/GPa, much larger compared to 0.1 kJ/mol/°C as a function of temperature [1]. (Commonly used units of pressure are related to each other as: atmospheric pressure: bar = 750.064 mm of Hg = 10⁵ Pa = 0.986923 atm = 1 kg/cm², psi = 14.50373 bar, 1 GPa = 10 kbar and 1 Mbar = 100 GPa.) In nature pressures vary over almost 63 orders of magnitude, i.e., from that of hydrogen in intergalactic space (∼10⁻³² bar) to that at the center of neutron stars (∼10³¹ bar). Further, in nature pressures could be static like the pressure at the center of the earth or at the bottom of an ocean, or dynamic like that caused by meteoric impacts witnessed recently in Russia or an earthquake causing the disastrous tsunami. Study of matter at extreme conditions helps in understanding several natural phenomena, synthesize new materials, has applications for energy [2] and defense technologies, provides insights into reaction chemistry of energetic materials, etc. Therefore high pressure investigations span a broad range of scientific disciplines (e.g., material science chemistry, physics, biology, and earth and planetary sciences, etc.).

When a material is compressed, its constituent atoms are brought closer, causing an increase in the overlap of electronic orbitals, resulting in changes in the hybridization of the outer electronic orbitals, bringing about the modifications in the nature of interatomic bonding and band structure. Significant increase in overlap of orbitals also manifests itself in terms of stronger repulsive forces, particularly between the nonbonded atoms. These changes propel the materials to evolve to new states having different physical properties, including structure, modifications occurring continuously or discontinuously. Understanding these alterations at extreme conditions provides insight into the nature of phase transformations, molecular to nonmolecular transitions [3], crystal to amorphous transitions [4], amorphous to amorphous transitions [5], chemical changes [6], increasing/lowering of melting temperature [7], insulator to metal transitions [8], valence transitions [9], Lifshitz transitions [10], changes in the dielectric function [11], refractive index [12–14] determination of the equation of state etc. [15,16] High-pressure studies also help to understand how the micro- and nanostructural aspects, such as crystallite size, dislocations, voids, and grain boundaries evolve on application of pressure [17].

Knowledge of high-pressure behavior of minerals like zircon can be very useful in determining peak pressures of meteoric impacts [18]. In fact, high-pressure studies of many minerals like pyrochlores, zircons, or glasses can throw light on their usefulness as nuclear encapsulants [19]. Application of pressure has also found its use in the chemical industry as there are several reactions that are accelerated on application of pressure, for example, the production of ammonia by the Habers process. Pressure plays an important role even in the food preservation industry and the health sector. Calcium hydroxyapatite is an important bioceramic and is the main constituent of teeth and bone tissues of human beings. Also, monocalcium monohydrate is widely used in bone and teeth cements, and it is known that masticatory stresses can ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• About the Editors
• Preface
• Chapter 1. Material Studies at High Pressure
• Chapter 2. Materials Under Shock Waves
• Chapter 3. Materials for Hostile Corrosive Environments
• Chapter 4. Materials for Hostile Chemical Environments
• Chapter 5. High Performance Polymer Nanocomposites for Structural Applications
• Chapter 6. Glasses and Glass-Ceramics for Vacuum and High-Temperature Applications
• Chapter 7. Natural Glasses Under Extreme Conditions
• Chapter 8. Protective Hard Coatings for Tribological Applications
• Chapter 9. Intermetallics and Alloys for High Temperature Applications
• Chapter 10. Synthesis and Characterization of Borides, Carbides, and Nitrides and Their Applications
• Chapter 11. High-Temperature Ceramics
• Chapter 12. Cold Plasma Processing of Materials for Extreme Conditions
• Chapter 13. Tailored Thermal Expansion Material for High-Temperature Applications
• Chapter 14. Materials Under Intense Laser Irradiation
• Chapter 15. Laser-Induced Vaporization–Mass Spectrometry Studies on Refractory Materials at Ultrahigh Temperatures
• Chapter 16. Nanoclusters Under Extreme Ionization Conditions
• Chapter 17. Materials Response Under Irradiation
• Chapter 18. Radiation–Matter Interaction and Radiation-Tolerant Oxides
• Chapter 19. Diamond-Based Radiation Detectors for Applications in Highly Corrosive Solutions and High-Radiation Fields
• Chapter 20. Severe Plastic Deformation of Materials
• Chapter 21. Materials in a High Magnetic Field
• Chapter 22. Properties of Materials Under High Electric Field
• Index