From Bulk to Nano: The Many Sides of Magnetism (Springer Series in Materials Science Book 117)

the Field Of Magnetism Is Rapidly Advancing In This New Millennium, Revealing An Ever-wider Diversity Of Magnetic Phenomena On More Than One Scale. With The Emergence Of Countless Applications Particularly On A Nanoscale, And Their Unpredictable Implications Mostly On A Macroscale, It May Seem That Different Aspects Of Magnetism Are Unrelated. Quite Often, The Overwhelming Amount Of Topics Discussed In The Professional Literature Views Only Parts Of A Field, Ignoring A Broader Context. Therefore, The Present Book Aims At Addressing The Relationship Between Apparently Unconnected Topics In Magnetism. Less Obvious Relationships Are Revealed Among Individual Fields On Various Scales, Making Them Better Understandable. Preface......Page 7 Contents......Page 10 Symbols......Page 15 Introduction......Page 19 1.1 Review of Certain Historic Magnetic Concepts......Page 20 1.2 Origins of Magnetism on an Atomic Scale......Page 24 1.3 Structure-Dependent Micromagnetism......Page 29 1.4 Towards Technological Advancements......Page 33 References......Page 34 2.1 Introduction......Page 36 2.2 A Basic Definition of Magnetic Barkhausen Noise......Page 37 2.3 Stress Effects......Page 41 2.4 Effects of Microstructure on MBN......Page 50 2.5 Competitiveness of MBN in Nondestructive Evaluation......Page 53 References......Page 55 3.1 The Interest in Magneto-optical Media......Page 58 3.2 Magnetoelectric Materials......Page 68 References......Page 81 4.1 Introduction......Page 88 4.3 What is Responsible for GMR?......Page 89 4.5 “Spin-down” vs. “Spin-up” Scattering: Magnetic Impurities......Page 90 4.8 The Role of Exchange Bias......Page 92 4.9 Ni–Fe Alloys......Page 93 4.11 Ni–Fe Alloys with Higher Fe Content......Page 94 4.12 Basic Principles of Storing Information Magnetically......Page 95 4.13 Materials for spin valve Sensors......Page 97 4.14 The Need for Proper Sensor Design......Page 98 4.16 Anisotropic Magnetoresistive Sensors......Page 99 4.18 GMR Sensors with CPP Geometry......Page 100 4.19 Dual Spin Valves......Page 101 4.20 Some GMR Multilayer Material Combinations......Page 102 4.22 The Nonmagnetic Spacer......Page 103 4.24 The Magnetic Tunnel Transistor......Page 104 4.25 Some Special Types of Ferromagnets......Page 105 4.26 Colossal Magnetoresistance......Page 106 4.27 CPP Geometry Preferred in Sensors......Page 107 4.28 Spin Valves in Commercial Applications......Page 108 References......Page 110 5.1 Encoding Information: Emergence of Spintronics......Page 116 5.2 Spin Injection......Page 117 5.3 Control of Spin Transport......Page 128 5.4.1 Detecting Single Spins......Page 136 References......Page 138 6.1 The Popularity of Magnetic Tapes......Page 145 6.2 Bit Patterned Magnetic Media......Page 150 6.3 Self-assembly and Magnetic Media......Page 155 6.4 Present Alternatives for Discrete Media Production......Page 161 References......Page 169 Reference......Page 177 Index......Page 178 The inspiration for this book can be traced back many years to two major works that in?uenced the author’s outlook on applied physics: FerromagnetismusbyR. Becker,W. D ̈ oring (Springer, Berlin 1939), and Ferromagnetism by R. M. Bozorth (IEEE Press, New York 1951). The former work is a collection of lectures held in the 1930s for ‘technicians’ attending a technical college. The German language in which the work was originally written was extremely convenient for the author of this present book, as it was for a long time the only comfortable technical language in an English speaking environment. Later on, upon encountering the work by Bozorth, it was a relief to see the clarity and eloquence of the subjects presented in English, despite the impressive thickness of the book. Bozorth’s work still constitutes a practical review for anyone in a multidisciplinary industry who comes across the various manifestations of magnetism. The popularity of both works is so enduring that they are regarded as highly academic, and yet extremely readable, a reference in their own right, still attracting many readers these days in industry and academia. The ?eld of magnetism progressed immensely in the twentieth century, and shows no signs of slowing down in the present one. It has become so vast that it is quite often viewed only in its parts, rather than as a whole. In today’smyriadofapplications,especiallyonananoscale,andtheirchangeable implications mostly on a macroscale, it often seems that di?erent aspects of reported work on magnetism are scattered and unrelated. This book deals with the latest achievements in the field of ferroelectric domain engineering and characterization at micron- and nano-scale dimensions and periods. The book collects the results obtained in the last years by world scientific leaders in the field, thus providing a valid and unique overview of the state-of-the-art and also a view to future applications of those engineered materials in the field of photonics This text addresses the relationship between apparently unconnected topics in magnetism. Less obvious relationships are revealed among individual fields on various scales, making them better understandable