Simplifying the theory of the Invar effect in iron-nickel alloys

Add to your list(s) Download to your calendar using vCal

• Chris Hooley (SUPA, University of St Andrews)
• Friday 28 August 2009, 15:30-16:30
• TCM Seminar Room, Cavendish Laboratory.

If you have a question about this talk, please contact Dr Jonathan Keeling.

Zero-temperature ab initio calculations of the lattice spacing of disordered iron-nickel alloys are presented. These show a strong negative correlation between the lattice spacing and the number of nearest-neighbour iron-iron pairs with antiparallel local moments. Based on the conjecture that this correlation persists at non-zero temperature, a simple theory is formulated that reproduces several experimental results on this class of Invar materials. We conclude that an alloy shows the Invar effect if the concentration of such pairs increases sufficiently rapidly over a broad interval of temperature.

Some of this work is available as a preprint, arXiv:0811.3673.

This talk is part of the Irregular seminars in TCM series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Combined TCM Seminars and TCM blackboard seminar listing
• Featured lists
• Hanchen DaDaDash
• Inference Group Summary
• Irregular seminars in TCM
• Lennard-Jones Centre external
• ME Seminar
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• PMRFPS's
• School of Physical Sciences
• TCM Seminar Room, Cavendish Laboratory
• Theory of Condensed Matter
• Thin Film Magnetic Talks
• few29

Note that ex-directory lists are not shown.