Rayleigh law: Difference between revisions

Content deleted Content added

Inline

Revision as of 13:03, 19 October 2010

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=\chi _{0}H+\alpha _{R}\mu _{0}H^{2}.

Here $\chi _{0}$ is the initial susceptibility, describing the reversible part of magnetisation reversal. The Rayleigh constant $\alpha _{R}$ describes the irreversible Barkhausen jumps.

References

^ Rayleigh, Lord (1887). "On the behaviour of iron and steel under the operation of feeble magnetic forces". Phil. Mag. 23: 225–248.

Kronmüller, Helmut; Fähnle, Manfred (2003). Micromagnetism and the microstructure of ferromagnetic solids. Cambridge University Press. p. 148. ISBN 00521331358. {{cite book}}: Check |isbn= value: length (help)
Cullity (1972). Introduction to magnetic materials. Addison-Wesley. p. 342.

This electromagnetism-related article is a stub. You can help Wikipedia by expanding it.

[1] Rayleigh, Lord (1887). "On the behaviour of iron and steel under the operation of feeble magnetic forces". Phil. Mag. 23: 225–248.

[1]

@@ Line 3: / Line 3: @@
 The '''Rayleigh law''' describes the behaviour of [[ferromagnetic]] materials at low [[magnetic field|fields]].
-[[Ferromagnetic]] materials consist of [[magnetic domains]]. When a small external field <math>H</math> is applied, domains parallel to the external field start to grow. In this region, [[domain wall]]s are moving. They are hindered by material defects. [[Lord Rayleigh]] investigated this first <ref>{{cite journal|last=Rayleigh|first=Lord|title=On the behaviour of iron and steel under the operation of feeble magnetic forces|journal=Phil. Mag.|volume=23|pages=225–248|year=1887|doi=10.1080/14786437108216375}}</ref> and quantified the magnetization <math>M</math> as a linear and quadratic term in the field:
+[[Ferromagnetic]] materials consist of [[magnetic domains]]. When a small external field <math>H</math> is applied, domains parallel to the external field start to grow. In this region, [[domain wall]]s are moving. They are hindered by material defects. [[Lord Rayleigh]] investigated this first <ref>{{cite journal|last=Rayleigh|first=Lord|title=On the behaviour of iron and steel under the operation of feeble magnetic forces|journal=Phil. Mag.|volume=23|pages=225–248|year=1887}}</ref> and quantified the magnetization <math>M</math> as a linear and quadratic term in the field:
 :<math>M = \chi_0 H + \alpha_R \mu_0 H^2.</math>