Home / English Posts (page 6)

English Posts

Atomic Size

Having the following three single crystals available: Sodium Chloride, Potassium Chloride and Rubidium Chloride, we have the possibility to perform XRD scanning for these three crystals and compare the results to obtain information on the atomic dimensions of the different ions. For this experiment we use the tel-x-ometer diffractometer configured …

Read More »

Graphite Structure

Graphite, the other form of elemental carbon in addition to diamond, adopts a very different covalent structure than that of the diamond to which different physical properties correspond. This structure consists of planar layers of carbon atoms forming a hexagonal mesh pattern. A graphite crystal consists of these layers of …

Read More »

Silicon & Germanium Crystal Structure

Diamond Cubic Crystal Structure Silicon and Germanium are examples of covalent crystals. In these solids the atoms are linked to each other by covalent bonds rather than by electrostatic forces or by delocalized valence electrons that work in metals almost like a “glue”. The most classic example of covalent crystal …

Read More »

Lithium Fluoride (LiF) Crystal

Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. The crystal structure of the Lithium Fluoride …

Read More »

Sodium Chloride (NaCl) Crystal

Sodium chloride, also known as salt or halite, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g/mol respectively, 100 g of NaCl contain 39.34 g Na and 60.66 g Cl. The salient features of its structure are: Chloride ions are ccp type of arrangement, i.e., it contains chloride …

Read More »

X-Ray Absorption

One of the first x-rays properties inspected was the ability of x-rays to penetrate solid matter. It has been found that materials such as gases, wood and rubber absorb relatively few x-rays. Conversely, even very thin sheets of heavy metals such as lead or platinum absorb nearly all x-rays incident …

Read More »

Laue Diffraction

Laue diffraction pattern, in X rays, a regular array of spots on a photographic emulsion resulting from X rays scattered by certain groups of parallel atomic planes within a crystal. When a thin, pencil-like beam of X rays is allowed to impinge on a crystal, those of certain wavelengths will be …

Read More »

Bragg Diffraction

Bragg diffraction (also referred to as the Bragg formulation of X-ray diffraction) was first proposed by William Lawrence Bragg and his father William Henry Bragg in 1913 in response to their discovery that crystalline solids produced surprising patterns of reflected X-rays (in contrast to that of, say, a liquid). They found that these crystals, at certain specific wavelengths and incident …

Read More »

Tel-X-Ometer Equipment

Recently we acquired a “vintage” equipment, rather old but in full working order : it is the Tel-X-Ometer x-ray diffractometer. A Tel-X-Ometer is an X-ray diffraction system device which is used to detect the absorption and reflection of X-rays i.e. a spectrometer. The device employs an X-ray tube with copper …

Read More »

X-Ray Diffraction DIY

With the X-ray tube we have recently acquired we want to try to make a diffractometer ! Introduction X-ray diffraction is one of the most important techniques for the study of crystalline solids. The X-ray diffraction technique is based on coherent elastic scattering : the macroscopic phenomenon of diffraction arises …

Read More »