Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Researchers explain odd oxygen bonding under pressure

Oxygen, the third most abundant element in the cosmos and essential to life on Earth, changes its forms dramatically under pressure transforming to a solid with spectacular colors. Eventually it becomes metallic and a superconductor.

The underlying mechanism for these remarkable phenomena has been fascinating to scientists for decades; especially the origin of the recently discovered molecular cluster (O2)4 in the dense solid, red oxygen phase.

Researchers from the Carnegie Institution's Geophysical Laboratory (GL), with colleagues* found that under pressure the molecules interact through their outermost electron clouds or "orbitals." Using a newly developed synchrotron technique at HPCAT, the lab's synchrotron facility at Argonne National Laboratory, the researchers found that the interaction of these half-filled orbitals increases with increasing pressure, changing the location of the orbitals, and bringing the four oxygen molecules together to form the (O2)4 clusters at a pressure about 10,000 times the atmospheric pressure (10 gigapascals). The study is published the week of August 4, in the Proceedings of the National Academy of Sciences.

"The molecular interaction in oxygen revealed by this study is due to the unique fact that oxygen's outmost orbital is half-filled with two unpaired electrons," explained Yue Meng, lead author of the study at HPCAT. "As the molecules are squeezed into smaller volumes at high pressure, electrons in the orbital inevitably move about, trying to pair with electrons in the neighboring molecules."

To study the dense solid phases of oxygen, the researchers developed the high-pressure inelastic X-ray scattering technique at the Advanced Photon Source, a high-brilliance synchrotron X-ray facility at Argonne. The technique uses the synchrotron X-ray beam to probe the electronic bonding change as a diamond anvil cell subjects a sample to many hundreds of thousands of atmospheres. The researchers combined their experimental results with theoretical calculations by collaborators to further reveal that there is an increasing interactions between the neighboring (O2)4 clusters in the red-colored oxygen, providing a mechanism for forming new bonding between the oxygen clusters in still higher pressure phases.

"The behavior of oxygen at high pressure demonstrates one of the most profound effects of pressure on matter, which transforms the colorless air we breath into colorful dense solids," continued Meng. "The drastic change in the appearance of this familiar gas is due to the bonding changes in oxygen induced by high pressure."

"This is the first demonstration of how new tools can be used to probe the subtle interactions between atoms and molecules that lead to the formation of entirely new crystal structures," said Russell J. Hemley, the GL's director. "These new structures may give rise to entirely new electronic, magnetic, and other physical properties that could lead to new technologies."

The formation of molecular clusters through the anti-bonding orbital called ?* is well known in organic chemistry and the electron delocalization in cluster orbitals provides several potentials for technical applications. "It is exciting to find that oxygen forms molecular clusters under high pressure through similar mechanism and this opens a possibility for new forms of materials at high pressure with potential for technical applications," Meng concluded.

Yue Meng | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Oasis of life in the ice-covered central Arctic
24.10.2016 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>