Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Watching the structure of glass under pressure

29.08.2014

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these properties by changing the atomic structure of glass. Now researchers at the University of California, Davis, have for the first time captured atoms in borosilicate glass flipping from one structure to another as it is placed under high pressure.


Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these properties by changing the atomic structure of glass. Now researchers at UC Davis have for the first time captured atoms in borosilicate glass flipping from a flat triangular configuration with three oxygen atoms around one boron to a tetrahedron, via a pyramidal intermediate.

Credit: Sabyasachi Sen, UC Davis

The findings may have implications for understanding how glasses and similar "amorphous" materials respond at the atomic scale under stress, said Sabyasachi Sen, professor of materials science at UC Davis. Sen is senior author on a paper describing the work published Aug. 29 in the journal Science.

Boron oxide is often added to glass to control a range of properties, including chemical durability, flow resistance, optical transparency and thermal expansion. Material scientists know that the structure around the boron atoms in borosilicate glass changes with pressure and temperature, switching from a flat triangular configuration with three oxygen atoms surrounding one boron atom to a four-sided tetrahedron, with four oxygen atoms surrounding one boron.

Until know, material scientists have only been able to study these structures in one state or the other, but not in transition. Sen and graduate student Trenton Edwards developed a probe that enabled them to make nuclear magnetic resonance (NMR) measurements of the environment of boron atoms in glass under pressures up to 2.5 Gigapascal.

They found that under pressure, the flat triangles of boron and three oxygen atoms first deform into a pyramid shape, with the boron atom pushed up. That may bring it close to another oxygen atom, and let the structure turn into a tetrahedron, with four oxygen atoms surrounding one boron.

Intriguingly, although glass is structurally isotropic and the stress on the glass is the same in all directions, the boron atoms respond by moving in one direction in relation to the rest of the structure.

"This is an unexpected finding that may have far-reaching implications for understanding a wide range of stress-induced phenomena in amorphous materials," Sen said.

###

The work was done in collaboration with Jeffrey Walton, project scientist with the UC Davis NMR Facility. It was funded by the U.S. National Science Foundation.

Andy Fell | Eurek Alert!

Further reports about: NMR Watching amorphous borosilicate glass implications materials pressure resistance respond structure structures temperature

More articles from Materials Sciences:

nachricht Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University

nachricht Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>