cullity - introduction to magnetic materials 2e (wiley, 2009)

[...]... in H to zero does not reduce M to zero Ferro- and ferrimagnetic materials can thus be made into permanent magnets The word hysteresis is from a Greek word meaning to lag behind,” and is today applied to any phenomenon in which the effect lags behind the cause, Fig 1.12 Typical magnetization curves of (a) a diamagnetic; (b) a paramagnetic or antiferromagnetic; and (c) a ferromagnetic of ferrimagnetic... Summary of Magnetically Hard Materials / 497 Applications / 498 14.14.1 Electrical -to- Mechanical / 498 14.14.2 Mechanical -to- Electrical / 501 14.14.3 Microwave Equipment / 501 14.14.4 Wigglers and Undulators / 501 477 xii CONTENTS 14.14.5 Force Applications / 501 14.14.6 Magnetic Levitation / 503 Problems / 504 15 MAGNETIC MATERIALS FOR RECORDING AND COMPUTERS 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8 Introduction. .. entirely new class of magnetic materials, the ferrites, was developed, explained, and put to use 2 A new tool Neutron diffraction, which enables us to “see” the magnetic moments of individual atoms, has given new depth to the field of magnetochemistry 3 A new application The rise of computers, in which magnetic devices play an essential role, has spurred research on both old and new magnetic materials And all... structure and X-rays to generations of metallurgists It was first published in 1967, with a second edition in 1978 and a third updated version in 2001, by Stuart R Stock His book on magnetic materials appeared in 1972 and was similarly successful; it remained in print for many years and was widely used as an introduction to the subjects of magnetism, magnetic measurements, and magnetic materials The Magnetics... electronic integrator appears, along with the alternating-gradient magnetometer, the SQUID, and the use of computers for data collection No big surprises here 3 There is a new chapter on magnetic materials for use in computers, and a brief chapter on the magnetic behavior of superconductors 4 Amorphous magnetic alloys and rare-earth permanent magnets appear, the treatment of domain-wall structure and... ) Fcurrent , or antiferromagnetic (i.e., MnO, FeO) ferromagnetic (i.e., Fe, Co, Ni) or ferrimagnetic (i:e:, Fe3 O4 ) Paramagnetic and antiferromagnetic substances can be distinguished from one another by magnetic measurement only if the measurements extend over a range of temperature The same is true of ferromagnetic and ferrimagnetic substances All substances are magnetic to some extent However, examples... and negative for diamagnetics, very small and positive for paramagnetics and antiferromagnetics, and large and positive for ferro- and ferrimagnetics The negative value of M for diamagnetic materials means that south poles are produced on the left side of the gap in Fig 1.11 and north poles on the right Workers in magnetic materials generally take the view that H is the “fundamental” magnetic field, which... Recording / 512 Possible Future Developments / 513 Magneto-Optic Recording / 513 Magnetic Memory / 514 15.8.1 Brief History / 514 15.8.2 Magnetic Random Access Memory / 515 15.8.3 Future Possibilities / 515 16 MAGNETIC PROPERTIES OF SUPERCONDUCTORS 16.1 16.2 16.3 16.4 16.5 505 517 Introduction / 517 Type I Superconductors / 519 Type II Superconductors / 520 Susceptibility Measurements / 523 Demagnetizing... section Since the unit of magnetic moment m is erg/oersted, the unit of magnetization M is erg/oersted cm3 However, it is more often written simply as emu/cm3, where “emu” is understood to mean the electromagnetic unit of magnetic moment However, emu is sometimes used to mean “electromagnetic cgs units” generically It is sometimes convenient to refer the value of magnetization to unit mass rather than... Ferromagnetic Resonance / 435 12.7.3 Nuclear Magnetic Resonance / 436 Problems / 438 12.1 12.2 12.3 13 Soft Magnetic Materials 13.1 13.2 13.3 Introduction / 439 Eddy Currents / 440 Losses in Electrical Machines / 445 13.3.1 Transformers / 445 13.3.2 Motors and Generators / 450 439 CONTENTS xi Electrical Steel / 452 13.4.1 Low-Carbon Steel / 453 13.4.2 Nonoriented Silicon Steel / 454 13.4.3 Grain-Oriented . Congress Cataloging-in-Publication Data is available: ISBN 97 8-0 -4 7 1-4 774 1-9 Printed in the United States of America 10987654321 CONTENTS PREFACE TO THE FIRST EDITION xiii PREFACE TO THE SECOND EDITION. Temperature Changes / 496 14.13 Summary of Magnetically Hard Materials / 497 14.14 Applications / 498 14.14.1 Electrical -to- Mechanical / 498 14.14.2 Mechanical -to- Electrical / 501 14.14.3 Microwave. university and industrial lab- oratories in the area of magnetic research. While Americans have made sizable contri- butions to the international pool of knowledge of magnetic materials, virtually all