Home / English Posts

English Posts

Polycrystalline Materials & Textures

Most inorganic solids are polycrystalline, including all common metals, many ceramics, rocks and ice. The extent to which a solid is crystalline (crystallinity) has important effects on its physical properties. Polycrystalline materials are made of crystallites. A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials. The orientation …

Read More »

Digital Radiography DIY

In this post we propose to use the Webcam ParticleDetector as a digital sensor to perform simple educational and demonstrative X-rays. The use of a webcam as a particle and radiation detector has been described in these articles : DIY Webcam Particle Detector, Webcam Particle Detector Measurements. The webcam, appropriately modified and …

Read More »

XRD Analysis of some Metals

We propose in this Post the XRD analysis of some metals. Gold Gold is a chemical element with symbol Au (from Latin: aurum) and atomic number 79. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal. It is one of the least reactive chemical elements and is solid under standard conditions. …

Read More »

XRD Analysis of Some Minerals

We propose in this Post the XRD analysis of some natural crystals and compunds. Fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. Fluorite crystallizes in a cubic motif. Crystal twinning is …

Read More »

X-Ray Absorption Spectroscopy

Theory When X-rays interact with matter, they lose energy due to Compton scattering, pair production, and photoelectric effects. The respective strength of these three effects depends on the energy of the radiation. In the our range of energy the photoelectric effect plays the most important role. Figure below shows the …

Read More »

X-Ray Emission

“White” Spectrum In striking the copper anode of the X-Ray tube the majority of electrons experience nothing spectacular; they undergo sequential glancing collisions with particles of matter, lose their energy a little at a time and merely increase the average kinetic energy of the particles in the target which in …

Read More »

Crystalline and Amorphous Solids

Introduction Silicon and oxygen are the most abundant elements on the earth’s crust. Silicon is found in nature always chemically combined with oxygen to which it binds with the strong chemical bond Si-O. This simple combination of these elements (Silicon Oxide) is known as Silica. Silicon dioxide exists naturally in …

Read More »

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 »