Russian researchers produce crystals of various colors and shades based on yttrium, aluminium and oxygen. Outwardly, they practically do not differ from well-known semiprecious garnet stones. However, artificially produced crystals possess higher solidity, and the color variety is much wider than that of their natural “relatives”.
Sometimes a minor thing is sufficient to change the situation beyond recognition. That is particularly important in chemistry, especially in chemistry of crystals. A crystal is like a huge building constructed from atom “bricks”: in case of one redundant atom or vice versa – and the building changes the shape, the quality of such structure decreasing. To color the crystal building, small amounts (hundredth parts) of certain metals (color promoters) are required. Such admixtures of chromium and iron make the first-class gems – rubies and sapphires – from aluminium oxide.
Nature spends several years to achieve the result, however the laboratories need one or two days to produce the same. Laboratories also grow natural garnets, but the quality has to be sacrificed to the speed. Crystals of a large size (in this case, they are convenient for the jewellers art) can be grown up from the melt containing silicon o?ide, aluminium oxide, ferric oxide. Yttrium-aluminium garnets without admixtures are colorless. By adding different rare-earth metals in the course of preparing these crystals, not only the desired color can be ensured to clystals, but also the required shade. The advantage of these crystals is also that the color promoters are better distributed in them, therefore, producing the crystals of uniform color and high degree of purity.
Sergey Komarov | alfa
Kirigami inspires new method for wearable sensors
22.10.2019 | University of Illinois College of Engineering
Fraunhofer LBF and BAM develop faster procedure for flame-retardant plastics
21.10.2019 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Researchers have succeeded in creating an efficient quantum-mechanical light-matter interface using a microscopic cavity. Within this cavity, a single photon is emitted and absorbed up to 10 times by an artificial atom. This opens up new prospects for quantum technology, report physicists at the University of Basel and Ruhr-University Bochum in the journal Nature.
Quantum physics describes photons as light particles. Achieving an interaction between a single photon and a single atom is a huge challenge due to the tiny...
A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)
It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...
Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.
Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...
A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.
The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...
02.10.2019 | Event News
02.10.2019 | Event News
19.09.2019 | Event News
22.10.2019 | Materials Sciences
22.10.2019 | Medical Engineering
22.10.2019 | Power and Electrical Engineering