There is no such thing on Earth: the alien mineral has unique physical properties

In a new study, an international team of researchers described unusual properties sample silicon tridymite — an extraterrestrial form of silicon dioxide, obtained from a meteorite that fell in Germany in 1724. 

The key uniqueness of this mineral is that it does not correspond to the usual laws of thermal conductivity. Silicon tridymite retains heat equally when heated to different temperatures. This makes it promising for industrial use. 

A group of scientists from the Fu Foundation School of Engineering and Applied Science at Columbia University, led by Professor Michele Simoncelli’s, in 2019 derived a single equation, that describes heat propagation both in crystals and through glass. This equation describes the intermediate behavior of defective or partially disordered materials, such as those used in thermoelectrics for waste heat recovery, perovskite solar cells, and thermal barrier coatings for heat shields.

Using their equation, the researchers studied a silica-based material and predicted that its extraterrestrial form — tridymite would be similar to a hybrid material — crystalline glass. They predicted, that the thermal conductivity of tridymite would remain constant and independent of temperature.

Simoncelli’s team collaborated with experimental groups led by Etienne Balan, Daniel Fournier, and Massimiliano Marangolo from the Sorbonne. To validate their predictions, the researchers conducted an experiment with a sample of tridymite silica from a meteorite that fell in Steinbach in 1724.

The results confirmed the hypothesis. This meteorite tridymite does indeed have an atomic structure intermediate between crystal and glass. Its thermal conductivity remains almost constant in the temperature range from -193°C to 106.8°C. 

This mineral is found not only in meteorites, but also on the surface of Mars. It is also interesting to note, that the unique atomic structures of silicon tridymite cannot be classified as either crystalline or glassy. Crystals are thought to have an ordered atomic lattice, while glass has a disordered, amorphous structure. Thus, silicon tridymite is a cross between the two. 

The thermal conductivity of each material is also determined by its atomic structure. The researchers emphasize, that the thermal conductivity of crystals usually decreases when heated and that of glass increases, but the thermal conductivity of of silicon tridymite remains unchanged. 

According to the researchers, similar tridymite materials can be used to more effectively control extreme temperatures during steel production, which emits a huge amount of carbon dioxide annually. At the moment, as noted in the study, production of 1 kg of steel leads to emissions of 1.3 kg CO₂.

Efficiency and environmental impact are largely determined by the way heat behaves in furnaces, in particular by the thermal conductivity of refractory materials that can withstand extreme temperatures. The study suggests that this temperature-independent conductivity arises from a balance between the corpuscular heat transfer in crystals and wave tunneling in glass. 

Furthermore, a fundamental understanding of heat flow in these hybrid crystal-glass materials also promises to shed light on the behavior of other excitations in solids, such as charge-carrying electrons and spin-carrying magnons.

The results of the study are published in the journal PNAS 

Source: Futurism