Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Yale scientists confirm how crystals form

04.11.2005


A team of researchers at Yale University is the first to devise a way to predict the microstructure of crystals as they form in materials, according to a report in the September issue of Applied Physics Letters.



Although there are theoretical models that predict grain size and ways to monitor the growth of individual crystals, this new method makes it possible to estimate grain size and therefore the properties of materials that are dependant on microstructure.

Researchers in many fields including materials science, geology, physical chemistry and biochemistry will now be able to tailor material properties that are sensitive to microstructure.


According to senior author Ainissa G. Ramirez, assistant professor of mechanical engineering, the Yale team monitored real-time images taken at two-second intervals while they heated crystallizing samples of nickel-titanium within a transmission electron microscope.

They directly determined the rate of crystal assembly (nucleation), and the rate that the crystals grew, by measuring the number of crystals and their change in size with time. Their results agree with the conventional Johnson-Mehl-Avrami-Kolmogorov method which only gives an overall crystallization rate, with the nucleation and growth rates coupled.

The novel contribution of this work is that the nucleation and growth rates are measured independently during crystallization and can be used to infer the grain size after crystallization is complete.

"We used the mathematics of crystallization in a new way," said Ramirez. "We found that our measured grain sizes and the mathematical predictions agreed over a broad range of temperatures. This method allows researchers to now explore the connection between structure and properties of different materials."

Janet Rettig Emanuel | EurekAlert!
Further information:
http://www.yale.edu

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Bodyguards in the gut have a chemical weapon

20.01.2017 | Life Sciences

SF State astronomer searches for signs of life on Wolf 1061 exoplanet

20.01.2017 | Physics and Astronomy

Treated carbon pulls radioactive elements from water

20.01.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>