Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Structural origin of glass transition

24.06.2015

Evolution of structural fluctuations in a supercooled liquid

A University of Tokyo research group has demonstrated through computer simulations that the enhancement of fluctuations in a liquid’s structure plays an important role as a liquid becomes a solid near the glass-transition point, a temperature below the melting point.


Snapshot of correlation of particle structure and dynamics at density of 0.97. Disks are colored according to the following criteria: white, low mobility and high order; black, high mobility and low order; cyan, low mobility and low order; and magenta, high mobility and high order.

Copyright : © 2015 John Russo, Hajime Tanaka.

This result increases our understanding of the origin of the glass transition and is expected to shed new light on the structure of liquids, thought until now to have been uniform and random.

Normally, a liquid changes to a solid when its temperature becomes lower than the melting point. However, some materials remain liquid even below the melting point, finally solidifying with further cooling (supercooling) at what is called the glass-transition point.

Despite intensive research over the years, its physical mechanism has remained elusive. One possibility is that increasing structural order develops in a supercooled liquid upon cooling, increasing the size of that structure and thus slowing down the dynamics and leading to the glass transition.

Because the structure of liquids that undergo a glass transition is disordered, it was difficult to detect fluctuations of such a structure, but a new method has been proposed recently.

This method does not depend on the type of liquid structure and has attracted much attention as it may enable extraction of structure size, which is key to understanding slow dynamics, for all liquids.

The research group of Professor Hajime Tanaka and Project Research Associate John Russo at the Institute of Industrial Science, the University of Tokyo, were only able to retrieve the separation distance of two particles using this method, finding instead that this method fails at extracting the correlation between more than two particles (many-body correlations) which are key for understanding the glass transition.

In a liquid composed of disk-shaped particles that do not deform no matter how much force is applied (a hard disc liquid), it is apparent that the dynamics of the liquid are dominated by a hexagonal lattice structure that is impossible to extract using this method.

“These findings not only support the physical mechanism proposed by this group that slow glassy dynamics is a consequence of the development of structural fluctuations in a supercooled liquid, but also provides a new insight into the liquid phase, which was believed to be uniform and random, and leads to a deeper understanding of the very nature of the supercooled liquid state,” says Professor Tanaka.


Associated links
UTokyo Research article

Euan McKay | ResearchSEA
Further information:
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Materials scientist creates fabric alternative to batteries for wearable devices
12.11.2018 | University of Massachusetts at Amherst

nachricht A new path through the looking-glass
12.11.2018 | Deutsches Elektronen-Synchrotron DESY

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 Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

Im Focus: Nanorobots propel through the eye

Scientists developed specially coated nanometer-sized vehicles that can be actively moved through dense tissue like the vitreous of the eye. So far, the transport of nano-vehicles has only been demonstrated in model systems or biological fluids, but not in real tissue. The work was published in the journal Science Advances and constitutes one step further towards nanorobots becoming minimally-invasive tools for precisely delivering medicine to where it is needed.

Researchers of the “Micro, Nano and Molecular Systems” Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, together with an international...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

In focus: Peptides, the “little brothers and sisters” of proteins

12.11.2018 | Life Sciences

Materials scientist creates fabric alternative to batteries for wearable devices

12.11.2018 | Materials Sciences

A two-atom quantum duet

12.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>