Scientists have created “black nitrogen”, which disappears if pressure drops. Thus, it was possible to prove that nitrogen is no exception to the rules of the periodic table and at high pressures it has the same structure as heavy elements in the same group. The results of their research are published in the journal Physical Review Letters.
At the University of Bayreuth, scientists were able to refute the special status of nitrogen. They created from it a crystalline structure resembling black phosphorus or arsenic under normal conditions. The structure contains two-dimensional atomic layers and therefore is of great interest for high-tech electronics.
In experiments conducted earlier, despite high pressure, nitrogen did not turn into similar structures. But similar similarities are observed at high pressures in neighboring groups led by carbon and oxygen. Researchers from the Laboratory of Crystallography at the University of Bayreuth and the Bavarian Research Institute of Experimental Geochemistry and Geophysics have created from nitrogen in laboratory conditions, at high pressure and high temperature, such a structure that is characteristic of black phosphorus, a particular variant of this element. In fact, it represents two-dimensional layers of nitrogen atoms, “stitched” into a single zigzag pattern. By its conductive properties, “black nitrogen” is similar to graphene, which means that it is promising for use in high-tech electronics. But its main minus is that when the pressure decreases, the “black nitrogen” turns back into ordinary nitrogen and disappears.
“Because of this instability, the industrial use of black nitrogen is currently not feasible. However, nitrogen remains a very interesting element. Our study shows that high pressures and temperatures can create structures and properties of materials that researchers did not know about before, ”says one of the authors of the study, Dr. Dominic Laniel.
It should be noted that the production of black nitrogen required, indeed, extreme conditions. The compression pressure was 1.4 million times higher than the pressure of the Earth’s atmosphere, and the temperature exceeded 4,000 degrees Celsius.