What is the Compton Effect? A. H. Compton observed that “when a monochromatic beam of high frequency (lower wavelength) radiation (e.g., X-rays and γ-ray) is scattered by a substance, the…
Month: November 2020
Bragg’s Spectrometer
Bragg’s Spectrometer Much of our knowledge about crystal structure and the structure of molecules as complex as DNA in crystalline form comes from the use of x-rays in x-ray diffraction…
Bragg’s Law
What is Bragg’s Law? Bragg’s law is a special case of Laue diffraction which determines the angles of coherent and incoherent scattering from a crystal lattice. When X-rays are incident…
Packing Factor (cubic, body and face)
What is the Packing Factor? Packing factor or Atomic Packing factor (APF) can be defined as the ratio between the volume of the basic atoms of the unit cell (which…
Lattice Parameters
What are Lattice Parameters? There are many shapes and patterns of unit cells. To describe these shapes, we use lattice parameters or variables that describe the orientation of the unit cell.…
Unit Cell
What is a Unit Cell? Crystal structures are made up of repeating units of atoms in well defined locations in a lattice. In order to describe these structures, it is…
Space Lattice
What is Space Lattice? The three-dimensional network of imaginary lines connecting the atoms is called the space lattice. A crystal is an arrangement in three dimensions of atoms or molecules…
Assumption of quantum theory of radiation
Fundamental assumptions of Quantum Mechanics In a particular representation and applied to a system consisting of a single, structure-less particle the fundamental assumptions of Quantum Mechanics are: The quantum state of…
Weins law and Rayleigh-Jeans law
The Rayleigh-Jeans Law: The Rayleigh-Jeans Law was a useful but not completely successful attempt at establishing the functional form of the spectra of thermal radiation. The energy density uν per…
Black Body Radiation Spectrum
Black Body Radiation: Black-body radiation is the thermal electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective…