Objectives_template Electroceramics Overview Electro Ceramics Web Course (NPTEL) Contact information of the course instructor: Ashish Garg, Associate Professor Department of Materials science and Engineering Indian Institute of Technology Kanpur Kanpur 208016, India Telephone: 0512-259-7904 Email: [email protected] Web: http://home.iitk.ac.in/~ashishg Introduction Electro-ceramics or broadly speaking electronic, optical and magnetic ceramics are useful in a variety of technological applications such as sensors, actuators, transducers, data storage devices etc. Some of the examples are Dielectric materials such as SiO2 are used as data storage elements in random access memories or RAMs Ferroelectrics such as BaTiO3 and PbTiO3 are used as sensors and actuators Magnetic oxides such as iron oxides are used for data storage in magnetic heads ZnO is used circuit protection materials in devices named as varistors ZrO2 stabilized with other oxides is used in fuel cells and batteries Hence, to understand these materials better and to engineer them as per our needs, we need to understand their science viz. their structure, defects in these materials, phenomenon of conduction, fundamentals of various functional properties. A sound understanding of these would (hopefully) enable us tailor the structure and properties of these material with good degree of control. Pre-requisites Basic courses on structure of materials, thermodynamics, and solid state physics Suited for final year undergraduate students of most disciplines and fresh graduate students. List of Topics Module Topics Equivalent Lectures (50-60 m each) 1: Structure of Ceramic Materials 5 2: Defect Chemistry and Equilibria 7 3: Diffusion and Conduction in Ceramics 7 4: Linear Dielectric Ceramics 8 5: Nonlinear Dielectric Ceramics 6 6: Magnetism and Magnetic Ceramics 5 file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1a.htm[5/25/2012 3:24:51 PM] Objectives_template 7: Superconducting Ceramics 1 8: Multiferroic and Magnetoelectric Ceramics 1 9: Synthesis Methods 1 Total number of equivalent lectures 41 file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1a.htm[5/25/2012 3:24:51 PM] Objectives_template Electroceramics Table of Contents Table of Contents 1. Structure of Ceramic Materials 1.1 Brief Review of Structure of Materials 1.2 A Brief Review of Bonding in Materials 1.3 Packing of atoms in metals 1.4 Interstices in Structures 1.5 Structure of Covalent Ceramics 1.6 Ionically Bonded Ceramic Structures 1.7 Compounds based on FCC Packing of ions 1.8 Other cubic structures 1.9 Orthogonal Structures 1.10 Structures based on HCP packing of ions 1.11 Summary 2. Defect Chemistry and Defect Equilibria 2.1 Point Defects 2.2 Kröger–Vink notation in a metal oxide, MO 2.3 Defect Reactions 2.4 Defect Structures in Stoichiometric Oxides 2.5 Defect Structures in Non-stoichiometric Oxides: 2.6 Dissolution of foreign cations in an oxide 2.7 Concentration of Intrinsic Defects 2.8 Intrinsic and Extrinsic Defects 2.9 Units for defect Concentration 2.10 Defect Equilibria 2.11 Defect Equilibria in Stoichiometric Oxides 2.12 Defect Equilibria in Non-Stoichiometric Oxides 2.13 Defect Structures involving Oxygen vacancies and interstitials: 2.14 Defect Equilibrium Diagram 2.15 A Simple General Procedure for constructing at Brouwer’s Diagram 2.16 Extent of non-stoichiometry 2.17 Example: Comparative behaviour of TiO2 and MgO vis-à-vis oxygen pressure 2.18 Electronic Disorder 2.19 Examples 2.20 Summary 3. Defects, Diffusion and Conduction in Ceramics 3.1 Diffusion 3.2 Diffusion Kinetics 3.3 Examples of Diffusion in Ceramics 3.4 Mobility and Diffusivity file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1b.htm[5/25/2012 3:24:51 PM] Objectives_template 3.5 Analogue to the electrical properties 3.6 Conduction in Ceramics vis-à-vis metallic conductors: General Information 3.7 Ionic Conduction: Basic Facts 3.8 Ionic and Electronic Conductivity 3.9 Characteristics of Ionic Conduction 3.10 Theory of Ionic Conduction Conduction in Glasses 3.11 Conduction in Glasses 3.12 Fast Ion Conductors 3.13 Examples of Ionic Conduction 3.14 Electrochemical Potential 3.15 Nernst Equation and Application of Ionic Conductors 3.16 Examples of Ionic Conductors in Engineering Applications 3.17 Summary 4. Dielectric Ceramics: Basic Principles 4.1 Basic Properties: Dielectrics in DC electric field 4.2 Mechanisms of Polarization 4.3 Microscopic Approach 4.4 Determination of Local Field 4.5 Analytical treatment of Polarizability 4.6 Effect of alternating field on the behavior of a dielectric material 4.7 Frequency dependence of dielectric properties: Resonance 4.8 Dipolar Relaxation i.e. Debye Relaxation is Polar Solids 4.9 Circuit Representation of a Dielectric and Impedance Analysis 4.10 Impedance Spectroscopy 4.11Dielectric Breakdown 4.12 Summary 5. Nonlinear Dielectrics 5.1 Introduction 5.2 Classification based on Crystal Classes 5.3 Ferroelectric Ceramics 5.3.1 Permanent Dipole Moment and Polarization 5.3.2 Principle of Ferroelectricity: Energetics 5.3.3 Proof of Curie-Weiss Law 5.3.4 Thermodynamic Basis of Ferroelectric Phase Transitions 5.3.5 Case I: Second order Transition 5.3.6 Case – II: First Order Transition 5.3.7 Ferroelectric Domains 5.3.8 Analytical treatment of domain wall energy 5.3.9 Ferroelectric Switching and Domains 5.3.10 Measurement of Hysteresis Loop 5.3.11 Structural change and ferroelectricity in Barium Titanate (BaTiO3) 5.3.12 Applications of Ferroelectrics 5.4 Piezoelectric Ceramics 5.4.1 Direct Piezoelectric Effect 5.4.2 Reverse or Converse Piezoelectric Effect file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1b.htm[5/25/2012 3:24:51 PM] Objectives_template 5.4.3 Poling of Piezoelectric Materials 5.4.4 Depolarization of Piezoelectrics 5.4.5 Common Piezoelectric Materials 5.4.6 Measurement of Piezoelectric Properties 5.4.7 Applications of Piezoelectric Ceramics 5.5 Pyroelectric Ceramics 5.5.1 Difference between and pyroelectric and ferroelectric material 5.5.2 Theory of Pyroelectric Materials 5.5.3 Measurement of Pyroelectric coefficient 5.5.4 Direct and Indirect effect 5.5.5 Common Pyroelectric Materials 5.5.6 Common Applications 5.6 Summary 6. Magnetic Ceramics 6.1 Magnetic Moments 6.2 Macroscopic view of Magnetization 6.3 Classification of Magnetism 6.4 Diamagnetism 6.5 Paramagnetism 6.6 Ferromagnetism 6.7 Antiferromagnetism 6.8 Ferrimagnetism 6.9 A Comparison 6.10 Magnetic Losses and Frequency Dependence 6.11 Magnetic Ferrites 6.12 Summary 7. High temperature Superconductors 7.1 Background 7.2 Meissner Effect 7.3 The critical field, Hc 7.4 Theory of Superconductivity 7.5 Discovery of high temperature superconductivity 7.6 Mechanism of high temperature superconductivity 7.7 Applications 7.8 Summary 8. Multiferroic and Magnetoelectric Ceramics 8.1 Introduction 8.2 Historical Perspective 8.3 Requirements of a magnetoelectric and multiferroic material 8.4 Magnetoelectric Coupling 8.5 Type I Multiferroics 8.6 Type II Multiferroics 8.7 Two Phase Materials 8.8 Summary file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1b.htm[5/25/2012 3:24:51 PM] Objectives_template 9. Synthesis Methods 9.1 Bulk Preparation Methods 9.2 Thin Film Preparation Methods 9.3 Thin film deposition: Issues 9.4 Summary file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1b.htm[5/25/2012 3:24:51 PM] Objectives_template Electroceramics General Bibliography General Bibliography The following are the books which can be referred for general reading. More references are provided in each module. Recommended Reading 1. Physical Ceramics: Principles for Ceramic Science and Engineering, Y.-M. Chiang, D. P. Birnie, and W. D. Kingery, Wiley-VCH 2. Introduction to Ceramics, 2nd Edition, W. D. Kingery, H. K. Bowen, D. R. Uhlmann, Wiley 3. Principles of Electronic Ceramics, by L. L. Hench and J. K. West, Wiley 4. Electroceramics: Materials, Properties, Applications, by A. J. Moulson and J. M. Herbert, Wiley 5. Nonstoichiometry, Diffusion and Electrical Conductivity in Binary Metal Oxides (Science & Technology of Materials), P.K. Kofstad, John Wiley and Sons Inc. Supplementary Reading 6. Introduction to Solid State Physics, C. Kittel, Wiley 7. Electrical Properties of Materials, L. Solymer and D. Walsh, Oxford University Press 8. Introduction of Solid State Physics, N.W. Ashcroft and N.D. Mermin, Brooks Cole 9. Solid State Physics, A.J. Dekker, Prentice-Hall 10. Transition Metal Oxides: An Introduction to Their Electronic Structure and Properties, P.A. Cox, Oxford University Press 11. Basic Solid State Chemistry, A.R. West, Wiley 12. Non-stoichiometric Oxides, O. Toft Sørensen, Academic Press 13. Dielectrics and Waves, A.R. von Hippel, John Wiley and Sons 14. Feynman Lectures on Physics, Volume 1-3, R.P. Feynman, Addison Wesley Longman 15. Materials Science and Engineering: A first course, V. Raghavan, Prentice Hall of India 16. Materials Science And Engineering: An Introduction, W.D. Callister, Wiley file:///C|/Documents%20and%20Settings/iitkrana1/Desktop/new_electroceramics_14may,2012/lecture1/1_1c.htm[5/25/2012 3:24:52 PM] Objectives_template Module 1: Structure of Ceramic Materials Introduction In this module, we will first review the structure and bonding in the materials in general followed by a brief discussion on how atoms pack together in the solids and what are the types of interstices present in various structures. Then we would briefly delve into the types of bonding with reference to the nature of materials. Together, this information will form the basis for structures in ceramic materials which are typically bonded with a mix of ionic and covalent bonding. Subsequently, we would discuss the structure of ceramic materials with purely covalent bonding followed by rather detailed description of ceramic materials with ionic bonding. These are essentially based on packing of anions closed packed forms where cations fill the interstices.