Laue

Max Theodor Felix Laue, later known as Max von Laue (1879–1960), was a German physicist who made foundational contributions to X-ray crystallography. In 1912–1913 he demonstrated that X-rays are diffracted by crystalline solids, providing direct evidence of the wave nature of X-rays and the periodic structure of crystals.

Laue conducted experiments using single crystals and beams of X-rays, including polychromatic (white) radiation, and recorded diffraction patterns on photographic plates. The resulting Laue photographs showed a constellation of diffraction lines whose geometry reflected the crystal lattice, enabling determination of crystal orientation and symmetry. This approach is now called the Laue method.

Laue formulated what are now known as the Laue equations, a set of conditions for diffraction expressed in terms of incident and diffracted wavevectors, indicating that diffraction occurs when their difference equals a reciprocal-lattice vector. The work helped establish the reciprocal lattice concept and the role of crystal symmetry in diffraction.

For this work, Laue was awarded the Nobel Prize in Physics in 1914 "for his discovery of the diffraction of X-rays by crystals." He continued to contribute to physics and to the advancement of crystallography, and his legacy persisted in the methods and concepts that underpin modern X-ray crystallography.

The name Laue endures in crystallography through concepts named after him, such as Laue groups, which classify diffraction patterns according to crystal symmetry, and by the enduring term Laue method in X-ray crystallography.