Rayleigh law

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This article is about the magnetic law. For optical scattering, see Rayleigh scattering.

The Rayleigh law describes the behaviour of ferromagnetic materials at low fields.

Ferromagnetic materials consist of magnetic domains. When a small external field H is applied, domains parallel to the external field start to grow. In this region, domain walls are moving. They are hindered by material defects. Lord Rayleigh investigated this first [1] and quantified the magnetization M as a linear and quadratic term in the field:

M = χ0H + αRμ0H2.

χ0 is the initial susceptibility, describing the reversible part of magnetisation reversal. The Rayleigh constant αR describes the irreversible Barkhausen jumps.

[edit] References

  1. ^ Rayleigh, Lord (1887). "On the behaviour of iron and steel under the operation of feeble magnetic forces". Phil. Mag. 23: 225-248. 
  • Kronmüller, Helmut (2003). Micromagnetism and the microstructure of ferromagnetic solids. Cambridge University Press. ISBN 00521331358. 
  • Cullity (1972). Introduction to magnetic materials. Addison-Wesley. 


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