Navigation Links
Nature of bonding determines thermal conductivity
Date:5/3/2011

nce, who is also currently a visiting professor at the University of Lige. "Phase change materials are very well suited because they are poor conductors of heat not only in the unordered but also in the ordered state, in contrast to semiconductors, for example," adds Prof. Matthias Wuttig from RWTH Aachen University. As part of an international research team, Hermann and Wuttig are investigating the reasons for this surprising material behaviour on alloys of germanium, antimony and tellurium. With the aid of sophisticated scattering experiments at the European Synchrotron Radiation Facility (ESRF) in Grenoble, they demonstrated that the bonding conditions between the atoms in the crystalline state as well as deviations from the perfect lattice structure influence the transmission of these vibrations through the material and thus reduce its thermal conductivity.

"The starting point for our investigations was the observation by our Japanese colleagues that the amorphous material is harder than the crystalline," says Hermann. "This contradicted all assumptions, but the measured stronger bonding forces between the atoms in the amorphous state fitted the picture." The Jlich scientists investigated how the atoms in the specimens vibrate both locally in the atomic range and also over longer distances. "In the crystalline material, we found harder vibrations for the long-range order and better conductivity for sound than in amorphous material. This is normal and is related to an increase in the order. However, we were surprised by the results for short-range vibrations in the crystal. They were softer. The short-range order in crystalline material is therefore lower than in amorphous material. This is very unusual."

On the basis of all the experimental results, the Aachen research group headed by Wuttig developed a model to explain the apparent contradictions. "Normally, the propagation of sound waves in material correlates with the thermal conductivit
'/>"/>

Contact: Angela Wenzik
a.wenzik@fz-juelich.de
49-246-161-6048
Helmholtz Association of German Research Centres
Source:Eurekalert

Page: 1 2 3

Related biology technology :

1. DOE JGI Director Eddy Rubin highlights the genomics of plant-based biofuels in the journal Nature
2. Natures Premium(R) Brand First Fresh Pork in North America to Carry DNA TraceBack(R) Seal of Authenticity
3. James L. Wittliff, Ph.D., FACB, to Present Predicting Breast Cancer Outcome with Gene Expression Signatures on the Ziplex(R) System at the Association for Molecular Pathology Conference, October 30
4. Genetic clock makers at UC San Diego publish their timepiece in Nature
5. MySignatureBook Certified Compliant With SAFE-BioPharma Digital Standard(TM)
6. Webcast Alert: Regulus Therapeutics, Alnylam Pharmaceuticals and Isis Pharmaceuticals Announce New Nature Publication on miR-21 Conference Call
7. Nature Medicine study shows Peregrines bavituximab can cure lethal virus infections
8. Research Published in Nature Medicine Shows Disruption of Chemokine Interactions Inhibits Atherosclerosis in Mice
9. Data Published in Nature Cell Biology Reveal Novel Function of Drug Target EpCAM in Cancer Cell Signalling
10. Light-speed nanotech: Controlling the nature of graphene
11. Nature Reviews Publishes Article About Jennerexs Multi-Mechanistic Cancer Therapeutic
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:7/1/2015)... CHANDLER, Ariz. , July 1, 2015 ... announced it has earned three Gold, three Silver, and ... Business Awards gala held in Chicago ... recognized as the premier business awards program in the ... and recognizes our company,s strength in developing leaders, cultivating ...
(Date:7/1/2015)... ... July 01, 2015 , ... NEMA 4 ... CTI’ new Medical Joysticks have an impermeable molecular barrier protection against bio-hazardous ... control device that will increase healthcare worker safety and reduce financial costs. , ...
(Date:6/30/2015)... , June 30, 2015 /PRNewswire/ - Resverlogix ... of common shares of Resverlogix have approved the ... Eastern Capital Limited of 5,600,000 units at a ... Placement"), each unit being comprised of one common ... aggregate proceeds of approximately CAD$15 million; and (ii) ...
(Date:6/30/2015)... June 30, 2015  Today, Americord Registry, one of the ... Andrew Horne , a partner at Kirkland & Ellis LLP, ... Logo - http://photos.prnewswire.com/prnh/20150630/226958LOGO   "We are ... Board," says Martin Smithmyer , CEO of Americord. "He ... career that will assist Americord,s growth and vision." ...
Breaking Biology Technology:Isagenix Earns Nine American Business Awards 2Isagenix Earns Nine American Business Awards 3Sanitized Medical Joysticks for a Safer and Healthier Work Environment 2Resverlogix Corp. Shareholders Approve Matters Relating to Licensing and Equity Arrangement 2Resverlogix Corp. Shareholders Approve Matters Relating to Licensing and Equity Arrangement 3Americord Registry Announces Andrew Horne as Advisory Board Member 2
... International Market Opportunities for the Company,s Medical ... ... PIP ), a biodefense company developing medical countermeasures,against biological and chemical ... a special UK government advisor., Lord Moonie will assist PharmAthene ...
... --,China Biologic Products, Inc. (OTC Bulletin Board: CBPO) ... in the People,s,Republic of China ("PRC"), today announced ... a.m. EDT on Friday, August 15, 2008, to ... in the live conference call, please dial the ...
... Duff & Phelps Corporation,(NYSE: DUF ), a ... announced that it has acquired the Lumin Expert ... specializes in,intellectual property dispute support and expert testimony. ... Lumin performs independent analyses of financial, economic and ...
Cached Biology Technology:Lord Lewis Moonie to Serve as Special UK Government Advisor to PharmAthene 2Lord Lewis Moonie to Serve as Special UK Government Advisor to PharmAthene 3China Biologic Products Announces Second Quarter 2008 Results Conference Call 2Duff & Phelps Acquires Lumin Expert Group To Build Global Intellectual Property Practice 2
(Date:6/25/2015)... , June 25, 2015 ... Market by Type (Swipe & Area), Technology, Material (Optical ... Healthcare, Commercial Security & Others) & Geography - ... marketsandmarkets, the said market is expected to reach ... 17.1%. Browse 76 market Tables ...
(Date:6/24/2015)... , June 24, 2015 The biologics safety ... major drivers for the market include growth of the ... new drug launches. Over the years, the number of ... 2001 and 2010, the FDA approved 225 drug applications ... WIPO, Europe accounted for 3,822 ...
(Date:6/24/2015)... , June 22, 2015 ... the addition of the "Huawei Ascend Mate ... report to their offering. Huawei,s technological ... the opposite direction than Apple,s and Samsung,s one. ... sensor developed by Fingerprint Cards, a main actor ...
Breaking Biology News(10 mins):Fingerprint Sensors Market Worth $14,500.07 Million by 2020 2Fingerprint Sensors Market Worth $14,500.07 Million by 2020 3Fingerprint Sensors Market Worth $14,500.07 Million by 2020 4Biological Safety Testing Market by Application, Product, & Test - Global Forecast to 2019 2Biological Safety Testing Market by Application, Product, & Test - Global Forecast to 2019 3Biological Safety Testing Market by Application, Product, & Test - Global Forecast to 2019 4Huawei Ascend Mate 7 Fingerprint Sensor - Reverse Costing Analysis 2
... Home to jaguars, harpy eagles and red-eyed tree frogs, ... the planet and are the most biodiverse ecosystems on ... are exceedingly rare has been a challenge in these ... the Smithsonian Tropical Research Institute show that interactions among ...
... soot emissions, the time table for carbon dioxide emission ... to achieve international climate policy goals such as those ... " Assessing the climatic benefits of black carbon mitigation ... Proceedings of the National Academy of Sciences (PNAS). ...
... Ronin, crucial to the self-renewal of embryonic stem cells, and a co-regulator ... enhancer element to control a gene "program" that stimulates growth of the ... group of researchers led by Baylor College of Medicine in ... . Dr. Thomas P. Zwaka , associate professor in ...
Cached Biology News:Tropical biodiversity is about the neighbors 2Aggressive action to reduce soot emissions needed to meet climate change goals 2Aggressive action to reduce soot emissions needed to meet climate change goals 3Ronin recruits protein 'allies' to sustain embryonic stem cell growth 2
Immunogen: Synthetic peptide: R(89) L A F T V D D N P T K P T T R Q R Y(107) Storage: -20 C, Avoid Freeze/Thaw Cycles...
...
... Interaction Kit provides an extremely fast ... isolate intact protein complexes. Unlike other ... multiple purification steps, this system takes ... Superflow Column for fast protein purification ...
... P Set from different Cynomolgus monkey ... organs maybe available upon request. ... from the whole set, and pay ... All Dr. P Set products ...
Biology Products: