Scientific Frontline® On-Site Search Engine by Google Co-op

Current UTC Time
 
News Home, where you will find the "Current Top Stories"The Communication Center contains current news briefs from major Universities, NASA, ESA, and the top three Aviation Mfg.Science section contains all the latest knowledge in Medical Research, Archeology, Biology, and other General Science NewsCurrent Earth Science and Environmental discoveries.The E.A.R., Environmental Awareness Report. E.A.R. will keep you advised of Environmental Alerts, Government, University, and public projects. All the current space discoveries from Hubble, Spitzer, Chandra X-Ray, ESO, Gemini, Subaru, ESA, NASA, and many more. The latest in space theories from leading astronomers and scientist from around the world.The Space Weather Forecast Center by Scientific Frontline, Current up-to-date space weather, forecasts, alerts and warnings. Images from SOHO, GOES, and STEREO. Plus solar observations from Erika RixCurrent space missions newsThe Cassini Main Page. Containing all the latest news from the Cassini Spacecraft around Saturn. Leading into Cassini status reports, The Cassini Gallery of all the latest images from Cassini. Seeing Saturn and all her moons like never before.Daily Sky maps, Celestial Events Calendar.Observatories Gallery, images from The Great Observatories and other leaders in astronomy.The Stellar Nights  Gallery, An amateur astronomical collection from John Crilly, Richard Handy, Erika Rix, and Paul RixCloudy Nights Telescope Reviews / An Atronomical Community.The latest in Computer, Nanotechnology, and General Technological advancements.The latest in Aviation achievements in civil, military, and space aviationThe World News Report,  news from the Voxant Viral Syndication, known as the Newsroom. Contains the latest videos from major news sources.The news archive from Scientific Frontline's past articles. A world of knowledge at your fingertips.Abstracts, Journals, and Technical papers maintained by Scientific Frontline. The Gateway to all the galleries in the Scientific Frontline collectionThe Scientific Frontline IYA 2009 CoverageResearch Department | Staff and Researchers OnlySite Related links from major universities, government and private research labs.Assorted Downloads related to space, science, aviation, including screensavers and ASTROMONY SOFTWARE, and other endorsed programs.Scientific Frontline Forum | HypercubeThe foundation of an online publication by SFL ORG. News Network called Scientific FrontlineContact page to Scientific Frontline / SFL ORG. News NetworkDisclaimer / Legal Notice for use of the SFL ORG. News Network's publication Scientific Frontline
an online publication of the SFL ORG. Educational News Network

Absorbing Hydrogen Fluoride Gas to Enhance Crystal Growth

Thursday, December 10, 2009

Newly patented method could improve superconductors, optical devices, and microelectronics

Vyacheslav Solovyov (left) and Harold "Bud" Wiesmann

Credit: Brookhaven National Laboratory
Two scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed a method to control the buildup of hydrogen fluoride gas during the growth of precision crystals needed for applications such as superconductors, optical devices, and microelectronics. The invention — by Vyacheslav Solovyov and Harold Wiesmann and recently awarded U.S. Patent number 7,622,426 — could lead to more efficient production and improved performance of these materials.

Materials with highly ordered crystalline atomic structures have enormous potential for energy-saving devices such as superconductors, which carry current with no energy loss, and high-speed electronics. Such crystals are typically grown from precursors deposited on substrates — for example: tapes, wires, or wafers, such as those used in the production of computer chips.

Adding fluorine to the precursors enhances the transfer of crystalline order from the substrate to the growing material. But fluorine also presents a problem because it leads to the buildup of hydrogen fluoride gas. Hydrogen fluoride slows down the reaction that converts the precursor to the desired material, sometimes even stopping crystal growth in its tracks.

You might think you could just vent the accumulating gas, but such methods have proven impractical,” said Wiesmann. For one thing, you’d have to remove the gas uniformly, to avoid variations in pressure that might affect crystal growth, which becomes more difficult over larger areas. Also, other gases necessary to crystal growth, such as oxygen and water vapor, get extracted along with the hydrogen fluoride, and re-injecting these gases introduces more pressure problems.

We’ve developed an improved method for removing hydrogen fluoride, based on absorption, that enhances the production of high-quality crystalline products.” Wiesmann said.

The new method incorporates a solid material capable of absorbing hydrogen fluoride (HF) gas inside the reaction chamber. The solid material can be attached to the inner surface of the reaction chamber or free standing, as long as it is made to conform to the shape of the precursor at a uniform distance. This allows uniform extraction of HF across large areas, thereby yielding crystalline end products that are uniform and homogeneous regardless of the shape of the precursor material or the area it occupies inside the reaction chamber.

A wide range of materials from alkaline earth oxides to materials containing calcium, sodium, or even activated carbon can be used as HF absorbers. The HF absorber material could be sprayed, painted, or otherwise deposited onto an inert support such as quartz or various oxides to attach it to the reaction chamber. Or it could be made from a powder and pressed into a form that conforms to the shape of the growing crystals.

Because these materials selectively absorb HF gas, water vapor, oxygen, and other gases that may be present and necessary for the conversion of the precursor material to finished crystals remain in the reaction vessel, undisturbed,” Solovyov said.

Solovyov and Wiesmann demonstrated the effectiveness of this approach when growing crystals of a common yttrium-barium-copper-oxide (YBCO) superconductor. In these experiments, YBCO crystals grew at a faster rate in the presence of a barium-oxide HF absorber when compared to conventional methods of crystal growth. The method also preserves the uniformity of the crystal growth environment so that superconducting properties do not vary along the length of the film.

This specific reaction serves as only one example, and the patent applies to the many possible modifications and variations in the materials used and produced.

The research was funded by DOE’s Office of Electricity Delivery and Energy Reliability.

More Information:
The new method is available for licensing and commercial development. For further information about the patent and commercial opportunities, contact Brookhaven Lab licensing specialist Kimberley Elcess, elcess@bnl.gov, 631 344-4151.





Source: Brookhaven National Laboratory

AddThis Social Bookmark Button

RSS FEEDS

Scientific Frontline®
The Comm Center
The E.A.R.®
World News Report
Space Weather Alerts
Stellar Nights®
Cassini Gallery
Mars Gallery
Missions Gallery
Observatories Gallery
Exploration Gallery
Aviation Gallery
Nature Trail Gallery

Scientific Frontline®
Is supported in part by “Readers Like You”
U.S Air Force/Lockheed Martin-Led Team Successfully Complete Environmental Testing Of First-Of-Its-Kind Missile Warning Satellite NEXT by CJ Johnson - 2006 - Cited by 59 - proteins from soil minerals by disrupting hydrogen bonds .... mM phenylmethylsulfonyl fluoride, purification was performed as Navigate Back or Forward Through Technology News, Related Page or Pick an Article From The News Ticker.
Member of

Scientific Frontline®, Stellar Nights®, E.A.R.®, and Environmental Awareness Report®”
Are Registered Trademarks of the
Online Publication of the SFL ORG. Educational News Network
Oklahoma City, Oklahoma USA
A Not-for-Profit Educational News Service
© 2005 - 2010 All Rights Reserved


Home | Comm. Center | Space Weather Center | Galleries | About Us | FAQ | Site Map | Contact Us | Privacy Policy | Terms of Service