| ABSTRACT | 第1-5页 |
| 摘要 | 第5-11页 |
| Chapter 1 Introduction and background | 第11-30页 |
| ·Basic conceptions of ferroelectrics | 第11-13页 |
| ·Mechanisms of polarization | 第11-12页 |
| ·Ferroelectrics and crystal symmetry | 第12-13页 |
| ·Characteristics and applications of ferroelectrics | 第13-18页 |
| ·Phase transition in perovskite ferroelectrics | 第13-14页 |
| ·Dielectric properties of ferroelectrics | 第14-15页 |
| ·Ferroelectric properties of ferroelectrics | 第15-17页 |
| ·Piezoelectric properties of ferroelectrics | 第17-18页 |
| ·Landau theory on ferroelectric phase transition | 第18-20页 |
| ·Point defects and its role in ferroelectrics | 第20-27页 |
| ·Type of defects: iso-valence dopant | 第20-21页 |
| ·Type of defects: hetero-valence dopant | 第21-24页 |
| ·Ferroelectric aging phenomena | 第24-27页 |
| ·Problems and dissertation objectives | 第27-30页 |
| Chapter 2 Defect symmetry principle in ferroelectrics | 第30-35页 |
| ·Introduction to defect symmetry principle | 第30-31页 |
| ·Aging process required by defect symmetry principle | 第31-32页 |
| ·Expected aging-induced multi-scale phenomena | 第32-34页 |
| ·Reversible domain switching | 第32页 |
| ·Double hysteresis loop and large recoverable electrostrain | 第32-34页 |
| ·Conclusions | 第34-35页 |
| Chapter 3 Large recoverable electrostrain in Mn-doped (Ba,Sr)Ti0_3 ceramics | 第35-47页 |
| ·Introduction | 第35-36页 |
| ·Experimental procedures | 第36-40页 |
| ·Composition design and fabrication of ceramic sample | 第36-38页 |
| ·Differential Scanning Calorimeter | 第38页 |
| ·Ferroelectric hysteresis loop and electrostrain measurements | 第38-40页 |
| ·Results and discussion | 第40-46页 |
| ·Curie temperature and phase structure | 第40页 |
| ·Large recoverable electrostrain based on defect symmetry principle | 第40-42页 |
| ·Frequency dependence of the recoverable electrostrain effect | 第42-43页 |
| ·Influence of Mn content on the recoverable electrostrain | 第43-44页 |
| ·Fatigue test of the recoverable electrostrain | 第44-46页 |
| ·Conclusions | 第46-47页 |
| Chapter 4 In-situ observation on reversible domain switching in aged Mn-doped BaTiO_3 single crystals | 第47-59页 |
| ·Introduction | 第47-48页 |
| ·Experimental procedures | 第48-51页 |
| ·Preparation of single crystals | 第48-49页 |
| ·Design of experimental setup | 第49-51页 |
| ·Results of aged and unaged samples | 第51-54页 |
| ·In-situ microscopy observation of domain patterns during electric field cycling | 第51-52页 |
| ·Electrostrain behavior associated with domain switching process | 第52-54页 |
| ·Discussion | 第54-58页 |
| ·Relation among microscopic defect symmetry, mesoscopic domain switching behavior, and macroscopic electrostrain properties | 第54-57页 |
| ·Comparison of our mechanism with others | 第57-58页 |
| ·Conclusions | 第58-59页 |
| Chapter 5 Aging effect in single-domain Mn-doped BaTi0_3 single crystals | 第59-68页 |
| ·Introduction | 第59-60页 |
| ·Experimental procedures | 第60页 |
| ·Growth and poling of single crystals | 第60页 |
| ·In-situ domain observation and hysteresis loop measurement | 第60页 |
| ·Results | 第60-63页 |
| ·Hysteresis loop of single-domain sample | 第60-62页 |
| ·Domain switching of single-domain sample during field cycling | 第62-63页 |
| ·Discussion | 第63-67页 |
| ·Volume effect as the primary origin of ferroelectric aging | 第63页 |
| ·Explanation on single domain aging by defect symmetry principle | 第63-65页 |
| ·Explanation on small signal aging by defect symmetry principle | 第65-67页 |
| ·Conclusions | 第67-68页 |
| Chapter 6 Different aging between A-site and B-site acceptor doped BaTi0_3 crystals | 第68-79页 |
| ·Introduction | 第68页 |
| ·Growth of single crystals and property measurements | 第68-70页 |
| ·Aging effect in A-site and B-site acceptor doped BaTi0_3 samples | 第70-71页 |
| ·Discussion on the aging difference | 第71-78页 |
| ·Explanation on the aging of acceptor doped sample by defect symmetry principle | 第71-73页 |
| ·Explanation on the different aging between A-site and B-site acceptor doped samples-symmetry conforming force | 第73-76页 |
| ·Calculation of symmetry conforming force in acceptor doped samples | 第76-77页 |
| ·Difficulty in explaining aging difference by previous aging models | 第77-78页 |
| ·Conclusions | 第78-79页 |
| Chapter 7 Aging in donor doped BaTi0_3 crystals and its origin | 第79-87页 |
| ·Introduction | 第79页 |
| ·Fabrication of ceramic samples and measurements | 第79-80页 |
| ·Aging effect in donor doped samples | 第80页 |
| ·Discussion on the origin of no aging in donor doped samples | 第80-86页 |
| ·Explaination on aging of donor doped samples by defect symmetry principle | 第81-84页 |
| ·Calculation of symmetry-conforming force in donor doped samples | 第84-85页 |
| ·Difficulty in explaining no aging in donor doped samples by previous aging models | 第85-86页 |
| ·Conclusions | 第86-87页 |
| Chapter 8 Conclusions and future work | 第87-90页 |
| ·Conclusions | 第87-88页 |
| ·Future work | 第88-90页 |
| Acknowledgments | 第90-91页 |
| References | 第91-95页 |
| Achievements | 第95页 |
