Magnetic Materials: Fundamentals and Device Applications ,

Nicola A.
Cambridge U. Press
New York
, 2003. $110.00, $40.00 paper (213 pp.). ISBN 0-521-81631-9, ISBN 0-521-01658-4 paper

Today’s Web surfers rely on magnetic devices to navigate the Internet, but their ancestors were navigating the high seas with magnetite compass needles hundreds of years ago. Thus, the impact of magnetic materials on science and technology is a phenomenon both ancient and modern. Magnetic materials currently excite the pioneering spirit in condensed matter physics (see, for example, the article by Neil Mathur and Peter Littlewood in Physics Today, January 2003, page 25). They also spur the entrepreneurial spirit, giving us data storage, sensors, motors, and transformers—to name some of the major applications.

Why then has there been no appropriate entry-level text for beginners? Existing texts do cover basic principles and applications, but the length and level of detail are unsuitable for an initial overview by undergraduates, graduates, or researchers new to the field. But now all that has changed. Fortunately, a good introductory book on magnetic materials is no longer an oxymoron.

Nicola Spaldin’s Magnetic Materials: Fundamentals and Device Applications is well written and hard to put down. It quickly takes the reader on an epic journey from the most basic principles of magnetism to the cutting edges of technology. Those who complete the odyssey will develop a coherent overview of magnetism and magnetic materials past, present, and future.

Spaldin is an associate professor in the materials department at the University of California, Santa Barbara (UCSB). Using various theoretical and computational methods, she examines the fundamental physics of new magnetic materials that may be technologically important. She has taught with much enthusiasm across a range of levels and has won several awards in the process. She has been granted NSF funding to improve the quality and relevance of graduate education at UCSB and has participated in international science education and outreach programs. Her passion for undergraduate teaching is reflected in the contents and style of her book.

Topics are developed in a concise manner and are efficiently interrelated. That interrelationship is particularly apparent in the opening text of each chapter. For example, in one chapter, diamagnetism is presented as an extension of the atomic physics that explains spin and orbital moments. In a subsequent chapter, paramagnetism is discussed as an effect that tends to overshadow diamagnetism. And in the next chapter, ferromagnetism and other types of magnetic order are developed out of paramagnetism using molecular fields, that is, the local effective fields due to the magnetic nature of the material. In addition, Spaldin has done an especially good job of writing the chapter on ferromagnetic domains and hysteresis.

The practical realities associated with the field of magnetism are well explained in Spaldin’s book. A whole chapter is devoted to magnetic data storage, and many examples throughout the text illustrate applications of the different categories of magnetic materials, even diamagnets. Spaldin also provides a timely discussion of the possible advantages of magneto-optical recording and magnetic semiconductors. On a practical and essential note, she covers SI and cgs systems. She then offers explicit interconversions, an important addition because of the persistent lack of consensus in the literature and in the workplace.

Spaldin imbues her narrative with the history of the subject. She gives names, dates, and original figures and references. For example, the Bitter technique is illustrated with a figure, taken from Francis Bitter’s original 1931 publication, showing magnetite deposits on a crystal of nickel. His method helped researchers to see, through microscopy, ferromagnetic domain boundaries. Even the quotations that open chapters are of historical, philosophical, and scientific significance.

The book works as a self-contained undergraduate course on magnetic materials. The exercises are imaginative and pitched at the appropriate level for beginners. The fully worked solutions are mathematically complete and contain a significant amount of helpful prose. Overall, Spaldin brings a nice literary style to the book. She refuses to stick to the language of dusty authoritarian texts and occasionally flirts with varying degrees of informality. At the risk of offending those who may actually think in the language of dusty authoritarian texts, Spaldin captivates readers with her style, which makes learning a pleasurable and effective experience.

Returning to the matter of substance, one criticism is the omission of classic subjects in magnetism, such as permanent magnets, the Landau theory of phase transitions, and the Ising and Heisenberg models. But omitting these subjects is acceptable because until now, I believe, it has been impossible to find a concise and accessible magnetics book for novices. But the long wait is over— Magnetic Materials is the missing book.