Materials Chemistry Materials Chemistry by Bradley D. Fahlman Central Michigan University, Mount Pleasant, MI, USA A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-1-4020-6119-6 (HB) ISBN 978-1-4020-6120-2 (e-book) Published by Springer, P.O. Box 17, 3300 AA Dordrecht, The Netherlands. www.springer.com Printed on acid-free paper First published 2007 Reprinted 2008 All Rights Reserved © 2008 Springer Science + Business Media B.V. No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. TABLE OF CONTENTS Preface ............................................................ ix Chapter 1. WHAT IS MATERIALS CHEMISTRY? .................... 1 1.1 HISTORICAL PERSPECTIVES . ............................ 2 1.2 CONSIDERATIONS IN THE DESIGN OF NEW MATERIALS . 5 1.3 DESIGN OF NEW MATERIALS THROUGH A “CRITICAL THINKING”APPROACH................................... 6 Chapter 2. SOLID-STATE CHEMISTRY ............................ 13 2.1 AMORPHOUS VS.CRYSTALLINESOLIDS.................. 13 2.2 TYPES OF BONDING IN SOLIDS . ..................... 14 2.2.1 IonicSolids......................................... 14 2.2.2 Metallic Solids . ................................ 16 2.2.3 Molecular Solids. ................................ 19 2.2.4 CovalentNetworkSolids.............................. 21 2.3 THECRYSTALLINESTATE................................ 21 2.3.1 Crystal Growth Techniques . ..................... 23 2.3.2 TheUnitCell ....................................... 25 2.3.3 CrystalLattices...................................... 28 2.3.4 CrystalImperfections................................. 41 2.3.5 Phase-Transformation Diagrams. ..................... 47 2.3.6 Crystal Symmetry and Space Groups . .............. 49 2.3.7 Physical Properties of Crystals . ..................... 53 2.4 THE AMORPHOUS STATE . ................................ 63 2.4.1 Sol–GelProcessing .................................. 63 2.4.2 Glasses............................................. 71 2.4.3 Cementitious Materials . ............................ 77 Chapter 3. METALS............................................... 87 3.1 MININGANDPROCESSINGOFMETALS................... 87 3.1.1 PowderMetallurgy................................... 92 v vi Table of Contents 3.2 METALLIC STRUCTURES AND PROPERTIES . 99 3.2.1 Phase Behavior of Iron–Carbon Alloys . .............. 99 3.2.2 Hardening Mechanisms of Steels . ..................... 106 3.2.3 StainlessSteels...................................... 118 3.2.4 NonferrousMetalsandAlloys ......................... 122 3.3 METAL SURFACE TREATMENTS FOR CORROSION RESISTANCE............................................. 135 3.4 MAGNETISMINMETALSANDALLOYS................... 138 3.5 REVERSIBLE HYDROGEN STORAGE . ..................... 143 Chapter 4. SEMICONDUCTING MATERIALS ...................... 153 4.1 PROPERTIES AND TYPES OF SEMICONDUCTORS .......... 153 4.2 SILICON-BASEDAPPLICATIONS.......................... 158 4.2.1 Silicon Wafer Production . ............................ 159 4.2.2 IntegratedCircuits................................... 162 4.3 LIGHT-EMITTING DIODES: THERE IS LIFE OUTSIDE OFSILICON!............................................. 202 4.4 THERMOELECTRIC (TE) MATERIALS. ..................... 207 Chapter 5. ORGANIC “SOFT” MATERIALS ........................ 221 5.1 POLYMER CLASSIFICATIONS AND NOMENCLATURE . 223 5.1.1 Polymerization Mechanisms . ..................... 227 5.2 “SOFT MATERIALS” APPLICATIONS: STRUCTURE VS. PROPERTIES.......................................... 250 5.2.1 Molecular Magnets. ................................ 256 5.2.2 Polymer Additives: Plasticizers and Flame Retardants . 264 Chapter 6. NANOMATERIALS .................................... 275 6.1 WHAT IS “NANOTECHNOLOGY”? . ..................... 278 6.2 NANOSCALE BUILDING BLOCKS AND APPLICATIONS . 280 6.2.1 Zero-Dimensional Nanomaterials . ..................... 282 6.2.2 One-Dimensional Nanostructures . ..................... 319 6.3 TOP-DOWN NANOTECHNOLOGY: “SOFT LITHOGRAPHY” . 342 Chapter 7. MATERIALS CHARACTERIZATION .................... 357 7.1 OPTICALMICROSCOPY .................................. 357 7.2 ELECTRON MICROSCOPY ................................ 360 7.2.1 TransmissionElectronMicroscopy ..................... 368 7.2.2 Scanning Electron Microscopy (SEM). .............. 390 7.2.3 Photoelectron Spectroscopy . ..................... 399 7.3 SURFACE CHARACTERIZATION TECHNIQUES BASEDONIONBOMBARDMENT.......................... 404 7.4 SCANNING PROBE MICROSCOPY . ..................... 412 7.5 BULK CHARACTERIZATION TECHNIQUES . .............. 418 Table of Contents vii Appendix A. TIMELINE OF MATERIALS AND TECHNOLOGICAL DISCOVERIES ....................................... 433 Appendix B. “THERE’S PLENTY OF ROOM AT THE BOTTOM” .... 441 Appendix C. MATERIALS-RELATED LABORATORY EXPERIMENTS ...................................... 453 C.1 CHEMICAL VAPOR DEPOSITION OF CARBON NANOTUBES............................................. 453 C.1.1 Background Information . ............................ 453 C.1.2 Procedure . ....................................... 455 C.2 SUPERCRITICAL FLUID FACILITATED GROWTH OF COPPER AND ALUMINUM OXIDE NANOPARTICLES . 457 C.2.1 Procedure . ....................................... 458 C.3 SYNTHESIS AND CHARACTERIZATION OF LIQUID CRYSTALS............................................... 460 C.3.1 Procedure . ....................................... 463 C.4 TEMPLATE SYNTHESIS AND MAGNETIC MANIPULATION OFNICKELNANOWIRES ................................. 465 C.4.1 Procedure . ....................................... 465 C.5 INTRODUCTION TO PHOTOLITHOGRAPHY . .............. 469 C.5.1 Procedure . ....................................... 469 C.6 SYNTHESIS OF GOLD NANOCLUSTERS . .............. 472 C.6.1 Procedure . ....................................... 472 Index ............................................................. 475 Preface Though most colleges and universities now have courses and degree programs related to materials chemistry, there is a need for a textbook that addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment. As I quickly discovered, trying to fill this void represented a daunting task of providing a suitable breadth and depth coverage of the rapidly evolving field of materials – all in a concise format. The material contained herein is most appropriate for junior/senior undergraduate students, as well as first-year graduate students in chem- istry, physics, and engineering fields. In addition, this textbook will be extremely use- ful for researchers in industry as an initial source to learn about materials/techniques, with references provided for more detailed investigation. After providing a historical perspective for the field of materials in the first chapter, the first concentration of the textbook focuses on solid-state chemistry. Though there are many popular textbooks that deal with this topic, my approach contains some unique perspectives. In addition to colored illustrations of archetypical crys- talline unit cells, digital photos of models are also provided to add clarity to their structures. Further, a large section on amorphous solids including sol–gel techniques and cementitious materials is provided – largely left out of most solid-state textbooks. The next chapter on metals contains a thorough treatment of traditional and powder metallurgical techniques, with a focus on the complex phase behavior exhibited by the Fe–C system and steels. However, also left out of most metallurgy textbooks, I cover topics such as corrosion inhibition, magnetism, hydrogen storage, and the structure/properties of other metallic classes, such as the coinage metals and other alloys, such as those exhibiting shape-memory properties. The next chapter deals with semiconducting materials, which consists of a discus- sion of band theory and semiconductor physics. Unique among other texts, I also describe in great detail the evolution of the transistor, with a discussion of current limitations and solutions currently being investigated by researchers in the field. Also described in this chapter is IC fabrication, including vapor deposition techniques, photolithography, and ion implantation. The current trends in applications such as LEDs/OLEDs, thermoelectric devices, and photovoltaics (including emerging tech- nologies such as dye-sensitized solar cells) are also provided in this chapter. ix x Preface Polymers and organic-based “soft” materials represent one of the largest materials classes; however, these materials are often left out of solid-state textbooks. Herein, I cover the chemistry of the five classes of polymers, from simple chains to com- plex branched dendritic architectures. Again, the approach is unique in that it covers traditional mechanisms and structure/property relationships for polymers, in addi- tion to advanced topics such as homogeneous catalysis, polymer additives, and self- healing polymers. A detailed discussion of “molecular magnets” is also provided in this chapter, due to their relatively mild syntheses and “soft” properties relative to traditional inorganic-based magnets. I devoted a significant effort in the next chapter