Putting molten history on the map - Phys.org [PDF]

18 mins ago - They squeezed the metal to extreme pressures: over a million times the Earth's atmospheric pressure. They

4 downloads 4 Views 332KB Size

Recommend Stories


Putting biomedical science on the scientific map
No matter how you feel: Get Up, Dress Up, Show Up, and Never Give Up! Anonymous

Putting rice on the table
Happiness doesn't result from what we get, but from what we give. Ben Carson

PdF History on Trial
If you want to become full, let yourself be empty. Lao Tzu

History Coverage Map
What we think, what we become. Buddha

murder on the map
Every block of stone has a statue inside it and it is the task of the sculptor to discover it. Mich

Putting Makeup on the Fat Boy
At the end of your life, you will never regret not having passed one more test, not winning one more

Putting the Focus on Student Engagement
If you are irritated by every rub, how will your mirror be polished? Rumi

Putting the Focus on Student Engagement
Sorrow prepares you for joy. It violently sweeps everything out of your house, so that new joy can find

Presentation on MAP 21.pdf
Suffering is a gift. In it is hidden mercy. Rumi

putting the focus on rheumatoid arthritis
Respond to every call that excites your spirit. Rumi

Idea Transcript


This website uses cookies to ensure you get the best experience on our website. More info

Nanotechnology

Physics

Earth

Astronomy & Space

Technology

Chemistry

Biology

Other Sciences

phys.org

search Home

Chemistry

Materials Science



December 13, 2017

Putting molten history on the map December 13, 2017, US Department of Energy 26 Like

Tweet

submit

reddit

Favorites

Email Featured

Why birds don't have teeth

Print

PDF

Popular

Last comments

May 23, 2018

10

How metals melt at high temperatures and pressures was clarified with a new x-ray scattering technique. A metal is sandwiched between two high-pressure diamond anvils. A laser melts the sample (right), while the structure is monitored with … more

Using the K computer, scientists predict exotic "di-Omega" particle May 24, 2018 1

At temperatures as hot as the sun and under pressures over a million times atmospheric pressure, the metal molybdenum melts. Tracking the molten history of the metal clarified the melting point, the border between solid and liquid phases. To track the melting process, a team focused an x-ray beam into the tight confines between two ultra-hard diamond micro-anvils. A laser heated the small volume. The x-ray beam allowed the tracking of fine features that uniquely formed from the melted metal and were a clear indication that melting had occurred.

Rehabilitating lactate: From poison to cure May 23, 2018

0

A simple mechanism could have been decisive for the development of life May

Characterization of high-pressure melting was used to map the important region of the temperatures and pressures just before a solid metal melts to become a pool of liquid. Measurements at extreme temperatures and pressures were made possible using a miniature diamond cell and a laser. This new x-ray scattering method enabled a more accurate phase map. It resolved differences between models and earlier experiments, and also revealed a new phase.

24, 2018

0

Team cracks code to cheap, small carbon nanotubes May 23, 2018 1

more »

The reliable detection of the melting point of materials at high pressure has been experimentally difficult. What is needed is a way to tell whether a sample is solid or liquid in the confines of a small high-pressure cell. With this new method, controlled laser heating and rapid cooling created a measurable structural signature that labelled a material's trip into the molten state. In the research, a team sandwiched a small sample of molybdenum metal between miniature diamond anvils. They squeezed the metal to extreme pressures: over a million times the Earth's atmospheric pressure. They used infrared laser beams to heat the sample volume to extreme temperatures up to that on the surface of the sun. At the same time, a bright highly focused x-ray beam generated diffraction patterns. These patterns are sensitive to the micro-crystalline state of the metal. Researchers found that the distribution of the initial crystalline grain sizes grew to larger diameters after initial heating.

Phys.org on Facebook Like 1.4M people like this. Sign Up to see what your friends like.

Email newsletter

email

Subscribe

When the sample melted, the grains disappeared. And, after rapid cooling, the liquid re-crystallized with much smaller grains. These assessments can be used to answer the question, even after the fact, of whether a particular temperature excursion caused the metal to melt. The structural changes are a new, more reliable criterion for exploring the phase map at extreme pressure and temperature. This new approach improved the accuracy of the molybdenum phase map and removed discrepancies between theory and less accurate measurements in the scientific literature. Also, the study of the microstructure close to but below the melting point revealed a new phase with highly textured re-arrangement of fine grains. It is similar to the textured structure found after deposition of metal films onto a substrate by vapor condensation. Learning to manipulate these microstructures has implications for a host of high-temperature applications, including mechanical properties of materials in engines and armaments. Explore further: Melting solid below the freezing point More information: Rostislav Hrubiak et al. Microstructures define melting of molybdenum at high pressures, Nature Communications (2017). DOI: 10.1038/ncomms14562 Journal reference: Nature Communications Provided by: US Department of Energy



8 shares feedback to editors



Follow Phys.org on Facebook Must read for science-minded people. Follow us for daily science and research news. facebook.com/physorg Related Stories

Recommended for you

Melting solid below the freezing point

A new guide for explorers of the submicroscopic world inside us May 25, 2018

January 23, 2017

Phase transitions surround us—for instance, liquid water changes to ice when frozen and to steam when boiled. Now, researchers at the Carnegie Institution for Science have discovered a new phenomenon of so-called metastability ...

Researchers from the University of Virginia have established new guidelines for scientists mapping out the body molecule by molecule to help us better understand how our cells use metals such as iron and magnesium to maintain ...

Selective laser melting additive technology method for material microstructure formation March 13, 2017

Why bioelectrodes for energy conversion are not stable

Scientists of Peter the Great St. Petersburg Polytechnic University (SPbPU) and Delft University of Technology developed a technology for obtaining new metal structures using a selective laser melting method, an additive ...

Researchers at the Ruhr-Universität Bochum have discovered why bioelectrodes containing the photosynthesis protein complex photosystem I are not stable in the long term. Such electrodes could be useful for converting light ...

Solid metal has 'structural memory' of its liquid state

Biosensor technologies to offer more effective approaches to disease treatment May 25, 2018

May 25, 2018

March 13, 2017

New work from a team including Carnegie's Guoyin Shen and Yoshio Kono used high pressure and temperature to reveal a kind of "structural memory" in samples

Every cell in our bodies is shaped by its outer coating, or biomembrane. This incredible, naturally created nanostructure wraps the cell in a supportive and

User comments

Commenting is closed for this article.

We recommend

Chemistry and Mineralogy of Earth’s Mantle. Experimental determination of melting in the systems enstatite-magnesite and magnesite-calcite from 15 to 80 GPa

A moissanite cell apparatus for optical in situ observation of crystallizing melts at high temperature

Andrew R. Thomson et al., American Mineralogist

Unusual plasticity and strength of metals at ultra-short load durations

Innovative oxide materials for electrochemical energy conversion and oxygen separation

G I Kanel et al., Physics-Uspekhi

Valery V. Belousov, Russian Chemical Reviews

Kaichi Suito et al., American Mineralogist

Federica Schiavi et al., American Mineralogist

Phase relations of CaCO3 at high pressure and high temperature

Formation and crystallisation of a liquid jet in a film exposed to a tightly focused laser beam* S.I. Anisimov et al., Quantum Electronics

Powered by

Top

Help

Science X Account

Feature Stories

Android app

Home

FAQ

Sponsored Account

Latest news

iOS app

Search

About

Newsletter

Week's top

Amazon Kindle

Mobile version

Contact

RSS feeds

Archive

© Phys.org 2003 - 2018, Science X network

Connect

Privacy Policy

Terms of Use

Smile Life

When life gives you a hundred reasons to cry, show life that you have a thousand reasons to smile

Get in touch

© Copyright 2015 - 2024 PDFFOX.COM - All rights reserved.