Braggtörvény

Braggtörvény, also known as the Bragg law, describes the diffraction of X-rays, electrons, and neutrons by a crystal lattice. It was formulated by Sir William Henry Bragg and his son Sir William Lawrence Bragg in 1913. The law states that constructive interference of scattered waves occurs when the path difference between adjacent planes of atoms in a crystal is an integer multiple of the wavelength of the incident radiation.

The mathematical expression for Bragg's law is nλ = 2d sinθ. In this equation, n is an integer representing the order of diffraction, λ is the wavelength of the incident radiation, d is the spacing between atomic planes in the crystal, and θ is the angle of incidence relative to the crystal planes. This equation is fundamental to X-ray crystallography, a technique used to determine the atomic and molecular structure of crystals. By measuring the angles at which diffraction peaks occur, scientists can deduce the spacing of planes within the crystal lattice.

The development of Bragg's law revolutionized the study of solid materials. It provided the first direct method for determining the arrangement of atoms in crystals, leading to breakthroughs in fields such as chemistry, physics, and materials science. Its applications extend to understanding the structure of biological molecules like DNA, as well as in the development of new materials with specific properties. The principles of Bragg's law are also observed in other forms of wave diffraction, such as neutron diffraction and electron diffraction.