What is Piezoelectricity? Piezoelectricity (also called the piezoelectric effect) is the appearance of an electrical potential (a voltage, in other words) across the sides of a crystal when you subject…
Year: 2020
Ferroelectricity
What is Ferroelectricity? Ferroelectricity is a property of certain nonconducting crystals, or dielectrics, that exhibit spontaneous electric polarization (separation of the centre of positive and negative electric charge, making one…
Laue’s Experiment
Laue’s Experiment Von Laue, in 1913, suggested that a crystal can act as a three dimensional grating for an X-ray beam. The experimental arrangement used to produce diffraction in…
Crystal-System Structure
The Seven Crystal Systems Triclinic System: All three axes are inclined towards each other, and they are of the same length. Based on the three inclined angles the various forms…
Seven Crystal Systems and Fourteen Bravais Lattices
What are Crystal Systems? In a crystal system, a set of point groups and their corresponding space groups are assigned to a lattice system. Of the 32 point groups that…
Compton Effect
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…
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.…