Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rewriting the periodic table at high pressure

15.08.2019

The periodic table has been a vital foundational tool for material research since it was first created 150 years ago. Now, Martin Rahm from Chalmers University of Technology presents a new article which adds an entirely new dimension to the table, offering a new set of principles for material research. The article is published in the Journal of the American Chemical Society.

The study maps how both the electronegativity and the electron configuration of elements change under pressure. These findings offer materials researchers an entirely new set of tools. Primarily, it means it is now possible to make quick predictions about how certain elements will behave at different pressures, without requiring experimental testing or computationally expensive quantum mechanical calculations.


At high pressure, extremely fascinating chemical structures with unusual qualities can arise, and reactions that are impossible under normal conditions can occur. In the dimension of pressure there is an unbelievable number of new combinations of atoms to investigate.

Credit: Yen Strandqvist/Chalmers University of Technology

"Currently, searching for those interesting compounds which appear at high pressure requires a large investment of time and resources, both computationally and experimentally. As a consequence, only a tiny fraction of all possible compounds has been investigated. The work we are presenting can act as a guide to help explain what to look for and which compounds to expect when materials are placed under high pressure," says Martin Rahm, Assistant Professor in Chemistry at Chalmers, who led the study.

At high pressures the properties of atoms can change radically. The new study shows how the electron configuration and electronegativity of atoms change as pressure increases. Electron configuration is fundamental to the structure of the periodic table. It determines which group in the system different elements belong to.

Electronegativity is also a central concept to chemistry and can be viewed as a third dimension of the periodic table. It indicates how strongly different atoms attract electrons. Together, electron configuration and electronegativity are important for understanding how atoms react with one another to form different substances. At high pressure, atoms which normally do not combine can create new, never before seen compounds with unique properties.

Such materials can inspire researchers to try other methods for creating them under more normal conditions, and give us new insight into how our world works.

"At high pressure, extremely fascinating chemical structures with unusual qualities can arise, and reactions that are impossible under normal conditions can occur. A lot of what we as chemists know about elements' properties under ambient conditions simply doesn't hold true any longer. You can basically take a lot of your chemistry education and throw it out the window! In the dimension of pressure there is an unbelievable number of new combinations of atoms to investigate" says Martin Rahm.

A well-known example of what can happen at high pressure is how diamonds can be formed from graphite. Another example is polymerisation of nitrogen gas, where nitrogen atoms are forced together to bond in a three-dimensional network. These two high-pressure materials are very unlike one another.

Whereas carbon retains its diamond structure, polymerised nitrogen is unstable and reverts back to gas form when the pressure is released. If the polymer structure of nitrogen could be maintained at normal pressures, it would without doubt be the most energy dense chemical compound on Earth.

Currently, several research groups use high pressures to create superconductors - materials which can conduct electricity without resistance. Some of these high-pressure superconductors function close to room temperature. If such a material could be made to work at normal pressure, it would be revolutionary, enabling, for example, lossless power transfer and cheaper magnetic levitation.

"First and foremost, our study offers exciting possibilities for suggesting new experiments that can improve our understanding of the elements. Even if many materials resulting from such experiments prove unstable at normal pressure, they can give us insights into which properties and phenomena are possible. The steps thereafter will be to find other ways to reach the same results," says Martin Rahm.

Read the article 'Squeezing All Elements in the Periodic Table: Electron Configuration and Electronegativity of the Atoms under Compression' in the Journal of the American Chemistry Society.

High pressure research:

The research has theoretically predicted how the nature of 93 of the 118 elements of the periodic table changes as pressure increases from 0 pascals up to 300 gigapascals (GPa). 1 GPa is about 10,000 times the pressure of the Earth's surface. 360 GPa corresponds to the extremely high pressure found near the Earth's core. Technology to recreate this pressure exists in different laboratories, for example, using diamond anvil cells or shock experiments.

"The pressure that we are used to on Earth's surface is actually rather uncommon, seen from a larger perspective. In addition to facilitating for high pressure material synthesis on Earth, our work can also enable a better understanding of processes occurring on other planets and moons. For example, in the largest sea in the solar system, many miles under the surface of Jupiter's moon Ganymede. Or inside the giant planets, where the pressure is enormous," says Martin Rahm.

The work was done using a mathematical model, in which each atom was placed in the middle of a spherical cavity. The effect of increased pressure was simulated through gradual reduction of the volume of the sphere. The physical properties of the atoms in different stages of compression could then be calculated using quantum mechanics.

###

More information:

At high pressure, atoms and molecules come closer together, and take on different atomic and electronic structures. A consequence of this is that materials that are usually semi-conductors or insulators can transform into metals.

Only some materials that form at high pressure retain their structure and properties when returned to ambient pressure.

The research was done together with colleagues Roberto Cammi, University of Parma, as well as Neil Ashcroft and Nobel prize winner Roald Hoffmann, both at Cornell University.

Contact:

Martin Rahm
Assistant Professor, Chemistry and Chemical Engineering
Chalmers University of Technology, Sweden
martin.rahm@chalmers.se
+46 31 772 30 50

Homepage of Rahmlab, Martin Rahm's research group

Media Contact

Joshua Worth
joshua.worth@chalmers.se
46-317-726-379

 @chalmersuniv

http://www.chalmers.se/en/ 

Joshua Worth | EurekAlert!
Further information:
https://www.chalmers.se/en/departments/chem/news/Pages/Rewriting-the-periodic-table-at-high-pressure-.aspx
http://dx.doi.org/10.1021/jacs.9b02634

More articles from Materials Sciences:

nachricht New 3D interconnection technology for future wearable bioelectronics
15.08.2019 | Institute for Basic Science

nachricht The first metal-organic coordination polymers were synthesized at the Samara Polytech
13.08.2019 | Samara Polytech (Samara State Technical University)

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

Im Focus: Vehicle Emissions: New sensor technology to improve air quality in cities

Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.

Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...

Im Focus: Self healing robots that "feel pain"

Over the next three years, researchers from the Vrije Universiteit Brussel, University of Cambridge, École Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI-Paris) and Empa will be working together with the Dutch Polymer manufacturer SupraPolix on the next generation of robots: (soft) robots that ‘feel pain’ and heal themselves. The partners can count on 3 million Euro in support from the European Commission.

Soon robots will not only be found in factories and laboratories, but will be assisting us in our immediate environment. They will help us in the household, to...

Im Focus: Scientists create the world's thinnest gold

Scientists at the University of Leeds have created a new form of gold which is just two atoms thick - the thinnest unsupported gold ever created.

The researchers measured the thickness of the gold to be 0.47 nanometres - that is one million times thinner than a human finger nail. The material is regarded...

Im Focus: Study on attosecond timescale casts new light on electron dynamics in transition metals

An international team of scientists involving the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg has unraveled the light-induced electron-localization dynamics in transition metals at the attosecond timescale. The team investigated for the first time the many-body electron dynamics in transition metals before thermalization sets in. Their work has now appeared in Nature Physics.

The researchers from ETH Zurich (Switzerland), the MPSD (Germany), the Center for Computational Sciences of University of Tsukuba (Japan) and the Center for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Working out why plants get sick

16.08.2019 | Life Sciences

Newfound superconductor material could be the 'silicon of quantum computers'

16.08.2019 | Physics and Astronomy

Stanford develops wireless sensors that stick to the skin to track our health

16.08.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>