Frustrated Materials and Ferroic Glasses (eBook)

Preface 6
Contents 9
Contributors 11
1 What Can Spin Glass Theory and Analogies Tell Us About Ferroic Glasses? 14
1.1 Introduction 14
1.2 Experimental Indications 15
1.3 Spin Glasses 17
1.3.1 Simulations 20
1.3.2 Soft Spins 21
1.4 Polar Glasses and Relaxors 22
1.4.1 Homovalent Relaxors 23
1.4.2 Heterovalent Relaxors 26
1.4.3 Polar Nanoregions 29
1.5 Itinerant Spin Glasses 32
1.6 Strain Glass 35
1.7 Conclusion 37
References 38
2 Spin Glasses: Experimental Signatures and Salient Outcomes 43
2.1 Introduction 43
2.2 What Is a Spin Glass Made of? 44
2.3 What Happens at Tg? 46
2.3.1 Dynamical Aspects of the Transition 46
2.3.2 A Thermodynamic Phase Transition 49
2.3.3 Spin Glass Transition: Open Questions 50
2.4 Slow Dynamics and Aging 52
2.4.1 DC Experimental Procedures 52
2.4.2 AC Experimental Procedures 55
2.5 Aging, Rejuvenation, and Memory Effects 57
2.5.1 Temperature Step Experiments 57
2.5.2 Memory Dip Experiments 59
2.5.3 Discussion 61
2.5.3.1 Hierarchical Picture 62
2.5.3.2 A Correlation Length for Spin Glass Order 63
2.6 Conclusions 64
References 65
3 Frustration(s) and the Ice Rule: From Natural Materialsto the Deliberate Design of Exotic Behaviors 69
3.1 Introduction 69
3.2 Common Systems 70
3.2.1 Water Ice 70
3.2.2 Spin Ice: Rare Earth Titanates 73
3.2.3 Artificial Spin Ice 74
3.2.3.1 Honeycomb Spin Ice 76
3.2.3.2 Square Ice 80
3.2.4 Particle-Based Ice 82
3.3 Theoretical Themes 83
3.3.1 Ice Rule, Topological Charges, and Topological Order 85
3.3.2 Ice Rule and Frustration(s) 89
3.3.2.1 Frustration of Pairwise Interaction 89
3.3.2.2 Vertex Frustration 90
3.3.2.3 Collective Frustration 92
3.4 Ice Manifolds and Emergent States by Artificial Design 95
3.4.1 Emergent Ice Rule, Charge Screening, and Topological Protection: Shakti Ice 95
3.4.2 Dimensionality Reduction: Tetris Ice 99
3.4.3 Polymers of Topologically Protected Excitations: Santa Fe Ice 101
3.4.4 Ice Rule Fragility in Particle Ices 102
3.5 Conclusion 105
References 105
4 Glassy Phenomena and Precursors in the Lattice Dynamics 112
4.1 Introduction 112
4.2 Phonon Localization in Relaxor Ferroelectrics 114
4.3 Coupling of PNRs to Phonons and the Ultrahigh Piezoelectricity in Relaxor-Based Ferroelectrics 122
4.4 Summary 125
References 127
5 Relaxor Ferroelectrics and Related Cluster Glasses 129
5.1 Mesoscopic Ferroic Glasses 129
5.2 Relaxor Ferroelectrics 131
5.2.1 Solid Solutions of PbMg1/3Nb2/3O3-PbTiO3 (PMN-PT) 131
5.2.2 Superglass Transition of PMN 131
5.2.3 Paraelectric PNR Precursor State 135
5.2.4 Percolation Transition of PNR 138
5.3 Superglass Transition in Uniaxial RelaxorFerroelectric SBN 143
5.3.1 Anisotropic PNR 143
5.3.2 Glass Transition of SBN80 145
5.4 Strain Glass as a Random Field System 150
5.5 Cluster Spinglass 154
5.6 Conclusion 159
References 160
6 Probing Glassiness in Heuslers via Density Functional Theory Calculations 163
6.1 Introduction 165
6.2 Magnetostructural Phase Transition of Rapidly Quenched Heusler Alloys 167
6.2.1 Order–Disorder Transitions and Classification of Phase Transitions 170
6.2.2 Influence of Annealing Process on the Isofield Magnetization Curves 171
6.2.3 Effect of Cobalt on the Isofield Magnetization Curves 173
6.3 Noncollinear Magnetism 178
6.4 Decomposition in Less Rapidly Quenched Heusler Alloys 180
6.5 Calculation of Mixing Energies in Heusler Alloys 183
6.6 Conclusions 187
References 188
7 Strain Glasses 193
7.1 A Brief History of Strain Glass 193
7.2 Origin of Strain Glass and a Generic Phase Diagram 195
7.3 Strain Glass Induced by Point Defects 197
7.4 Strain Glass Induced by Dislocations and Nano-Precipitates 204
7.5 Competing Consequences of Defect-Doping in Ferroelastic/Martensite Systems: New Martensite vs. Strain Glass 207
7.6 Summary and Outlook 211
References 212
8 Discrete Pseudo Spin and Continuum Models for Strain Glass 214
8.1 Introduction 214
8.2 A Continuum Landau Model with Elastic Interactions and Defects 216
8.3 A Strain Glass with Randomly Distributed Dopants 218
8.4 A Discrete Pseudo Spin Model for Strain Glass 220
8.5 Coupling Information Sciences with Landau Models 223
8.6 Summary 225
References 225
9 Mesoscopic Modelling of Strain Glass 227
9.1 Introduction 228
9.1.1 Canonical Structural Glasses 229
9.1.2 Geometrical Frustration 230
9.2 Anisotropy and Intrinsic Disorder 231
9.2.1 Anisotropy 231
9.2.2 Intrinsic Disorder 233
9.2.3 Cluster Glasses 234
9.2.3.1 Strain Glass 236
9.3 Modelling Strain Glass 238
9.3.1 The Model 238
9.3.1.1 Anisotropy 239
9.3.1.2 Disorder 240
9.3.1.3 Numerical Simulations 240
9.3.2 Preliminary Analysis: Origin of Glassy Behavior 241
9.3.3 Structural Morphology 243
9.3.4 Thermodynamics 245
9.3.5 Thermomechanics 247
9.3.5.1 Elastocaloric Response 251
9.4 Modelling Strain-Mediated Magnetic Glass 252
9.5 Summary and Conclusions 255
References 256
10 Phase Field Model and Computer Simulation of Strain Glasses 260
10.1 Martensitic Transformation and Strain Glass Transition in Ferroelastic Systems 261
10.1.1 Phase Field Modeling of Martensitic Phase Transformation 262
10.1.2 Role of Point Defects 265
10.2 Phase Field Simulation of Strain Glass Transition 266
10.3 Unique Properties Associated with Strain Glass Transition and Strain Glass State 273
10.4 Challenge and Opportunity 274
References 276
Index 280