Professor Erich Peter Wohlfarth and the Wohlfarth Lecture Series

The Wohlfarth lecture is given annually at the Magnetism 20xx series of conferences (previously given at CMMP) in recognition of the outstanding contribution made by Peter Wohlfarth to the field of magnetism. The lecture is jointly sponsored by the IOP Magnetism Group and the IEEE UKRI Magnetics Chapter.

Professor Erich Peter Wohlfarth

Professor Wohlfarth was born in Germany in 1924 but emigrated to England with his family in 1933 where he attended Bingley Grammar School in Yorkshire. He gained his BSc in Physics from the University of Leeds in 1946 and his Ph.D. in 1948 under the direction of E.C. Stoner. After finishing his studies he became a lecturer in the Department of Mathematics at Imperial College where he remained until his death in 1988.

Professor Wohlfarth is perhaps best known today for his theory of fine particle magnetism which is captured in the famous classic 1948 paper [1] of Stoner and Wohlfarth on the magnetic hysteresis of single domain particles. This model has formed the basis of many contributions to the understanding magnetization reversal processes and their application in magnetic recording and permanent magnets. The range of contributions made by Professor Wohlfarth is evident from his list of publications [2]. In particular he made an important contribution to understanding the origin of ferromagnetism in metals such as iron, and the variation of magnetic properties with temperature. This work based on the band model of ferromagnetism is often called the Stoner-Wohlfarth itinerant electron model. It remains the simplest model which explains ferromagnetism in metals.

He was one of those rare theoretical physicists with a real interest in materials science and an experimental pragmatism. One of the reasons his work remains important today is its outstanding quality over a wide spectrum of activities reaching from the most intricate theoretical physics of ferromagnetism via magnetic hysteresis and anhysteresis to the materials and engineering problems of magnetic recording, which remains the key technology in data storage to the present day.

Peter Wohlfarth was a great researcher and teacher who, with his brilliant intellect, intuition, and refreshing common sense, his ingenious way of thinking, and his true and untiring devotion to work, left an indelible mark on a generation of scientists and engineers. But beyond this and above all he was a great human being and an entirely unforgettable personality to all of those who were fortunate enough to know him.

A more complete version of the life and the many contributions to science and society made by Professor Wohlfarth can be found in his obituary which is ref [2] below.

[1] E. C. Stoner and E. P. Wohlfarth, “A mechanism of magnetic hysteresis in hetrogeneous alloys,” Phil. Trans. Roy. Soc., vol. A240, pp. 599-642, 1948. (Also reproduced as IEEE Trans. Magn. 27 (1991) 3475).

[2] Erich Peter Wohlfarth, IEEE Trans. Magn. 27 (1991) 3469.

Wohlfarth Lecture Series:

The purpose of the Wohlfarth lecture is to acknowledge the contribution made by Professor E P Wohlfarth to the study of magnetism in the UK and worldwide. The lecture also serves to promote the broad areas of technical interest of Professor Wohlfarth and his commitment to international collaboration in scientific research and magnetism in particular.

The lecturer is chosen in alternate years by the IOP Magnetism Group and the UK and Republic of Ireland IEEE Magnetism Chapter.

The organisation of the lecture should reflect the broad interests of Professor Wohlfarth in both theory and experimental research, and also his personal commitment both to the UK Institute of Physics, the IEEE Magnetics Society and other learned bodies. In organising the lecture the following guidelines will be followed:

  • The lecture will take place annually at a national meeting organised by the Institute of Physics, or an international conference on magnetism held within the UK. It will be a plenary lecture
  • The lecture will be co-organised and co-sponsored by the Institute of Physics Magnetism Group and the Magnetics Society of the UKRI branch of the IEEE Magnetics Society
  • The lecturer will be acknowledged by the award of a certificate to be prepared by the Institute of Physics Magnetism Group and the IEEE Magnetics Society
  • The lecturer will be introduced by the Chairman of the nominating society or his representative and a vote of thanks will be presented at the end of the lecture by the Chairman or his nominee of the non-nominating society

Selection criteria:

The lecture will be on a topic within the broad areas of interest of Professor Wohlfarth. These are:

  • Fine particle magnetism
  • Magnetism of thin films, surfaces and interfaces
  • Permanent magnets and soft magnetic materials
  • Structure and properties of magnetic materials including transport properties
  • Ferromagnetism
  • Magnetism of itinerant electrons
  • The magnetic properties of correlated electron systems
  • Magnetic recording technology
  • Theory and experiment associated with the above topics
  • The membership will be asked to nominate suitable candidates for the Wohlfarth lecture by email or any other mechanism suggested by the Committees of both bodies. The Committees will resolve, either by discussion or ballot amongst the members of the Committee, the nomination for the Wohlfarth lecturer, and discussion between the respective Chairmen will take place to resolve any differences
  • The nomination received in one year may be carried over for the consideration in subsequent years, but will not be automatic
  • Over a 4-year time scale the nominating bodies will endeavour to ensure a balance between theory and experiment in terms of the topic of the lecture
  • Over a 4-year period the nomination will be approximately 2 UK lecturers: 2 overseas lecturers. The nominated lecturer will generally be a person in the mid part of their career, approaching the peak of their scientific career

Wohlfarth Lecturers:

1989 Piers Coleman, Rutgers University

1990 R. Coehoorn, Philips Research Labs, Eindhoven

1991 None – for information “Definitely not given at CMMP 91 in Birmingham; no record in IOP minutes suggests lecture was not given. This may have been an IEEE year due to an early suggestion in the  minutes of Roger Cowley.”

1992 Rolf Allenspach, ETH Zurich

1993 Peter Grünberg, Julich

1994 Roy Chantrell, Bangor

1995 Dominique Givord, Lab Louis Neel, Grenoble

1996 David Awschalom, UCSB

1997 Mary Doerner, IBM Almaden

1998 Stephen Hayden, Bristol

1999 Tony Bland, Cambridge

2000 Russell Cowburn, Durham

2001 None

2002 WolfgangWernsdorfer, Lab Louis Neel, Grenoble

2003 Amanda Petford-Long, Oxford

2004 Bob Stamps, Univ. Western Australia

2005 Thomas Schrefl, Sheffield

2006 Stuart Parkin, IBM

2007 Caroline Ross, MIT

2008 Matthias Bode, Hamburg/Argonne

2009 Stephen Blundell, Oxford

2010 Guido Meier, Hamburg

2011 Christopher Marrows, Leeds

2012 Steven Bramwell, UCL

2013 None (CMMP finished and Magnetism 2014 not started)

2014 Atsufumi Hirohata, York, “Nano-Spintronic Devices” presented at Magnetism 2014 conference in Manchester.

2015 Laura Heyderman, ETH Zurich/PSI, Switzerland, “Shedding light on artificial ferroic systems”, presented at Magnetism 2015 in Leeds.