Aimed primarily at experimental chemists, physicists, electronic engineers and material scientists interested in particulate and granular magnetic materials, this textbook is the culmination of more than forty years' research into the subject.
The text is divided into two parts. Part One covers the basic physics of magnetism from a relatively low level, including an explanation of some of the unusual terminology in magnetism such as the idea of poles and flux, whose origins are little understood. The complexity of the unit systems in magnetism are also presented. Thereafter a brief review of the principles of domain theory is presented and thermal activation effects and their correct measurement are discussed in some detail. The topic of exchange bias, where an antiferromagnetic material is grown in intimate contact with a ferromagnet, is presented in significant detail, reviewing old theories and numerical models but then focusing on what has become known as the York Model of Exchange Bias, which is now universally accepted as the model that describes the behaviour of exchange bias systems when grown in the form of granular thin films.
In Part Two a detailed description of ferrofluids is presented, including a simple method for their preparation and the various engineering applications in vacuum seals, loudspeakers, sink float separation, and the alignment of non-magnetic entities.A description is provided of the phenomenon of magnetic hyperthermia, which is a developing technology with significant potential applications in medicinal therapies. Other applications of magnetic nanoparticles in biomedicine are also presented. An extensive discussion of magnetic information storage in conventional recording systems is described, including the brief history of the development of this technology, whose scale is now enormous, as most of the cloud computing systems in current use are based on hard drive technology.
Kevin O'Grady, Emeritus Professor of Experimental Physics, School of Physics, Engineering and Technology, University of York, Gonzalo Vallejo Fernandez, Senior Lecturer, School of Physics, Engineering and Technology, University of York, Atsufumi Hirohata, Professor in Nanoelectronics, School of Physics, Engineering and Technology, University of York
Kevin O'Grady is an internationally recognized expert in magnetic materials and in particular magnetisation reversal processes, having written more than 300 refereed works on the subject. He is a former President of the IEEE Magnetics Society and is the founder of a small company, Liquids Research Ltd., based in North Wales, that manufactures Ferrofluids and other magnetic liquids.
Gonzalo Vallejo Fernández received an undergraduate degree in physics from the University of Oviedo in 2002, followed by a PhD in magnetism from the University of York in 2007. After a two year post-doc at York, he relocated to the University of Glasgow as a Research Fellow. In 2010 he returned to York and joined the Department of Physics as a Lecturer/Assistant Professor in 2012. He is currently a Senior Lecturer/Associate Professor in the School of Physics, Engineering and Technology at the University of York.
Atsufumi Hirohata received BSc and MSc degrees in physics from Keio University, Japan, in 1995 and 1997, respectively, and obtained his PhD in physics from the University of Cambridge in 2001. He then moved to the Francis Bitter Magnet Laboratory in the Massachusetts Institute of Technology in 2002 as a Postdoctoral Associate. He then became a Researcher at the Department of Materials in Tohoku University, Japan, in 2003 and at the Frontier Research System in RIKEN, Japan, in 2005. He became a Lecturer in the Department of Electronics in the University of York in 2007.
