# Bragg's law

(Difference between revisions)
 Revision as of 06:54, 27 March 2006 (view source)← Older edit Revision as of 07:37, 27 March 2006 (view source)Newer edit → Line 3: Line 3: == Definition == == Definition == - Provide the definition of the entry (in English) here. + Bragg's law provides the condition for a plane wave to be diffracted by a family of lattice planes: + +
+ 2 ''dhkl'' sin θ = ''n'' λ. +
+ + where [itex] d_{hkl} [/itex] is the '''lattice''' spacing, θ the angle between the wavevector of the incident plane wave and the reflecting planes, λ its wave length and ''n'' is an integer, the order of the reflection. It is equivalent to the diffraction condition in reciprocal space and to the [[Laue equations]].

## Revision as of 07:37, 27 March 2006

Loi de Bragg (Fr). Bragg Gesetz (Ge). Ley de Bragg (Sp). Legge di Bragg (It)

## Definition

Bragg's law provides the condition for a plane wave to be diffracted by a family of lattice planes:

2 dhkl sin θ = n λ.

where dhkl is the lattice spacing, θ the angle between the wavevector of the incident plane wave and the reflecting planes, λ its wave length and n is an integer, the order of the reflection. It is equivalent to the diffraction condition in reciprocal space and to the Laue equations.

## History

Bragg (1890-1971) presented his derivation of the reflection condition at a meeting of the Cambridge Philosophical Society on 11 November 1912. His paper was published in 1913 (Bragg W.L., 1913, The Diffraction of Short Electromagnetic Waves by a Crystal, Proc. Cambridge Phil. Soc., 17, 43-57. For details, see P. P. Ewald, 1962, IUCr, 50 Years of X-ray Diffraction, Section 5, page 64.