Scientists discover unusual materials properties at ultrahigh pressure

October 20, 2020

An international team of scientists from NUST MISIS (Russia), Linköping University (Sweden) and University of Bayreuth (Germany) found that, contrary to the usual physical and chemical laws, the structure of some materials does not condense at ultrahigh pressures. Actually, it forms a porous framework filled with gas molecules. This happened with samples of Os, Hf, and W put together with N in a diamond anvil at a pressure of one million atmospheres. The discovery is described in Angewandte Chemie.

"You can transform a pencil lead into diamond if you squeeze it very hard" -- this fact heard by many of us in childhood sounded like a complete nonsense. However, science laws make it clear that there is no miracle: both pencil lead and diamond are formed by the same chemical element, i.e. carbon, which actually forms a different crystal structure under very high pressure. It makes sense: ar pressure the empty space between atoms decreases and the material becomes denser. Until recently, this statement could be applied to any material.

It turned out that a number of materials can become porous at ultrahigh pressure. Such a conclusion was made by a group of scientists from NUST MISIS (Russia), Linköping University (Sweden) and University of Bayreuth (Germany). The team examined three metals (hafnium Hf, tungsten W, and osmium Os) with an addition of N when placed in a diamond anvil at a pressure of 1 million atmospheres, which corresponds to a pressure at a depth of 2.5 thousand kilometers underground. Scientists believe that it was the combination of pressure and nitrogen N that influenced the formation of a porous framework in the crystal lattice.

"Nitrogen itself is quite inert and without ultrahigh pressure it would not react with these metals in any way. Materials without nitrogen would simply condense in a diamond anvil. However, a combination gave an amazing result: some of the nitrogen atoms formed a kind of reinforcing framework in the materials, allowing the formation of pores in the crystal lattice. Consequently, additional nitrogen molecules entered the space", said Professor Igor Abrikosov, head of the theoretical research group and NUST MISIS Laboratory for the Modeling and Development of New Materials.

The experiment was initially conducted physically by Sweden and German part of the group, and then its results were confirmed by theoretical modeling on NUST MISIS supercomputer. Scientists emphasize that the research is fundamental, i.e. materials with such properties are not yet created for specific tasks. At the moment, the very fact that previously unthinkable modifications of materials can be obtained is important.

A whole new step will be to preserve such materials at normal atmospheric pressure. In one of the previous works, scientists managed to preserve a special modification of rhenium nitride. Currently, rapid cooling to critical low temperatures is considered as one of the ways to stabilize new materials.
-end-
The work of the research team is marked as "Hot Paper" by the editorial board of Angewandte Chemie, and an illustration from the article is placed on the back cover. The research is supported by the Russian Science Foundation (Project No. 18-12-00492).

National University of Science and Technology MISIS

Related Nitrogen Articles from Brightsurf:

Chemistry: How nitrogen is transferred by a catalyst
Catalysts with a metal-nitrogen bond can transfer nitrogen to organic molecules.

Illinois research links soil nitrogen levels to corn yield and nitrogen losses
What exactly is the relationship between soil nitrogen, corn yield, and nitrogen loss?

Reducing nitrogen with boron and beer
The industrial conversion of nitrogen to ammonium provides fertiliser for agriculture.

New nitrogen products are in the air
A nifty move with nitrogen has brought the world one step closer to creating a range of useful products -- from dyes to pharmaceuticals -- out of thin air.

'Black nitrogen'
In the periodic table of elements there is one golden rule for carbon, oxygen, and other light elements.

A deep dive into better understanding nitrogen impacts
This special issue presents a selection of 13 papers that advance our understanding of cascading consequences of reactive nitrogen species along their emission, transport, deposition, and the impacts in the atmosphere.

How does an increase in nitrogen application affect grasslands?
The 'PaNDiv' experiment, established by researchers of the University of Bern on a 3000 m2 field site, is the largest biodiversity-ecosystem functioning experiment in Switzerland and aims to better understand how increases in nitrogen affect grasslands.

Reducing reliance on nitrogen fertilizers with biological nitrogen fixation
Crop yields have increased substantially over the past decades, occurring alongside the increasing use of nitrogen fertilizer.

Flushing nitrogen from seawater-based toilets
With about half the world's population living close to the coast, using seawater to flush toilets could be possible with a salt-tolerant bacterium.

We must wake up to devastating impact of nitrogen, say scientists
More than 150 top international scientists are calling on the world to take urgent action on nitrogen pollution, to tackle the widespread harm it is causing to humans, wildlife and the planet.

Read More: Nitrogen News and Nitrogen Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.