Featured Research

from universities, journals, and other organizations

What planets are made of: Findings establish counterintuitive potential planet-forming materials

Date:
April 24, 2013
Source:
Stony Brook University
Summary:
Scientists have made a startling prediction that challenges existing chemical models and current understanding of planetary interiors -- magnesium oxide, a major material in the formation of planets, can exist in several different compositions.

Structures of the newly predicted magnesium oxides: On the left, MgO2; on the right, Mg3O2. Green – Mg atoms, red – O atoms. Isosurfaces show regions of high electron localization.
Credit: Image courtesy of Stony Brook University

A team of researchers led by Artem R. Oganov, a professor of theoretical crystallography in the Department of Geosciences, has made a startling prediction that challenges existing chemical models and current understanding of planetary interiors -- magnesium oxide, a major material in the formation of planets, can exist in several different compositions. The team's findings, "Novel stable compounds in the Mg-O system under high pressure," are published in the online edition of Physical Chemistry Chemical Physics. The existence of these compounds -- which are radically different from traditionally known or expected materials -- could have important implications.

"For decades it was believed that MgO is the only thermodynamically stable magnesium oxide, and it was widely believed to be one of the main materials of the interiors of the Earth and other planets," said Qiang Zhu, the lead author of this paper and a postdoctoral student in the Oganov laboratory.

"We have predicted that two new compounds, MgO2 and Mg3O2, become stable at pressures above one and five million atmospheres, respectively. This not only overturns standard chemical intuition but also implies that planets may be made of totally unexpected materials. We have predicted conditions (pressure, temperature, oxygen fugacity) necessary for stability of these new materials, and some planets, though probably not the Earth, may offer such conditions," added Oganov.

In addition to their general chemical interest, MgO2 and Mg3O2 might be important planet-forming minerals in deep interiors of some planets. Planets with these compounds would most likely be the size of Earth or larger.

The team explained how its paper predicted the structures in detail by analyzing the electronic structure and chemical bonding for these compounds. For example, Mg3O2 is forbidden within "textbook chemistry," where the Mg ions can only have charges "+2," O ions are "-2, and the only allowed compound is MgO. In the "oxygen-deficient" semiconductor Mg3O2, there are strong electronic concentrations in the "empty space" of the structure that play the role of negatively charged ions and stabilize this material. Curiously, magnesium becomes a d-element (i.e. a transition metal) under pressure, and this almost alchemical transformation is responsible for the existence of the "forbidden" compound Mg3O2.

The findings were made using unique methods of structure prediction, developed in the Oganov laboratory. "These methods have led to the discovery of many new phenomena and are used by a number of companies for systematically discovering novel materials on the computer -- a much cheaper route, compared to traditional experimental methods," said Zhu.

"It is known that MgO makes up about 10 percent of the volume of our planet, and on other planets this fraction can be larger. The road is now open for a systematic discovery of new unexpected planet-forming materials," concluded Oganov.

This work is funded by the National Science Foundation and DARPA.


Story Source:

The above story is based on materials provided by Stony Brook University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Qiang Zhu, Artem R. Oganov, Andriy O. Lyakhov. Novel stable compounds in the Mg–O system under high pressure. Physical Chemistry Chemical Physics, 2013; DOI: 10.1039/C3CP50678A

Cite This Page:

Stony Brook University. "What planets are made of: Findings establish counterintuitive potential planet-forming materials." ScienceDaily. ScienceDaily, 24 April 2013. <www.sciencedaily.com/releases/2013/04/130424125444.htm>.
Stony Brook University. (2013, April 24). What planets are made of: Findings establish counterintuitive potential planet-forming materials. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2013/04/130424125444.htm
Stony Brook University. "What planets are made of: Findings establish counterintuitive potential planet-forming materials." ScienceDaily. www.sciencedaily.com/releases/2013/04/130424125444.htm (accessed September 23, 2014).

Share This



More Matter & Energy News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Company Copies Keys From Photos

Company Copies Keys From Photos

Newsy (Sep. 22, 2014) A new company allows customers to make copies of keys by simply uploading a couple of photos. But could it also be great for thieves? Video provided by Newsy
Powered by NewsLook.com
Rockefeller Oil Heirs Switching To Clean Energy

Rockefeller Oil Heirs Switching To Clean Energy

Newsy (Sep. 22, 2014) The Rockefellers — heirs to an oil fortune that made the family name a symbol of American wealth — are switching from fossil fuels to clean energy. Video provided by Newsy
Powered by NewsLook.com
Raw: SpaceX Rocket Carries 3-D Printer to Space

Raw: SpaceX Rocket Carries 3-D Printer to Space

AP (Sep. 22, 2014) A SpaceX Rocket launched from Cape Canaveral, carrying a custom-built 3-D printer into space. NASA envisions astronauts one day using the printer to make their own spare parts. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Inside London's Massive Sewer Tunnel Project

Inside London's Massive Sewer Tunnel Project

AP (Sep. 22, 2014) Billions of dollars are being spent on a massive super sewer to take away London's vast output of waste, which is endangering the River Thames. (Sept. 22) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins