Crystals consisting of wildly mixed ingredients - so-called high-entropy materials - are currently attracting growing scientific interest. Their advantage: they are particularly stable at extremely high temperatures. A team at the Swiss Federal Laboratories for Materials Science and Technology (Empa) is producing and researching these ceramic materials, which have only been known since 2015.
Nature strives for chaos. One measure of disorder is entropy. If disorder increases, processes usually occur spontaneously and the path back to the previously prevailing order is blocked. Crystals are considered to be the opposite of disorder. In a crystal structure, all the lattice elements are neatly arranged next to each other in the smallest possible volume. This makes the idea that crystals could be stabilized by the force of entropy and thus create a new class of material all the more astonishing. But this is exactly what Empa is trying to do. Entropy-stabilized materials/crystals are still a young field of research. If they are exposed to high temperatures, they remain stable, because "re-sorting" would lead to greater order. In order to test a variety of possible combinations, the researchers have built a special synthesis device, the "Tubular Flow Reactor", in which chemical mixtures can be tested one after the other as if on an assembly line.
Numerous applications are envisaged, including for catalytically active materials, energy storage devices, high-performance batteries, superconducting ceramics or catalysts for car exhaust gases and other chemical production processes.
