Colloquia

Seminars

• Astronomy and Space Physics
• Atomic, Molecular, and Optical Physics
• Condensed Matter
• Fluids and Plasmas
• Particle Physics
• Calendar of Events

Graduation Commencement

Colloquium Abstract

Date: April 24th (130 Smith Hall, 11:00am)

Speaker: J.M.D. Coey, School of Physics and CRANN, Trinity College, Dublin, Ireland

Title: Magnetic Materials - What are the limits?

Abstract:
The 20th century witnessed an unsustainable exponential improvement in the properties of magnetic materials. Although there was no advance whatsoever in the maximum Curie point (Co - 1390 K) or magnetization (Fe 70Co 30 – 1.96 MAm -1) there was spectacular progress in controlling coercivity. Passing from the hard and soft steels of 1900, whose coercivity differed by a factor of one hundred to the vast range of materials available now, whose coercivity spans eight orders of magnitude, we have broken the shape barrier and ensured that billions of magnets are manufactured every year for a host of useful applications. The magnetic content of an average global citizen’s shopping cart will be examined, and the prospects of further, post-exponential improvement will be assessed. The opportunities and challenges of scalability, the key benefit of magnetic circuits, will be critically examined.