Navigation Links
Probing atomic chicken wire
Date:3/4/2011

"When you have graphene sitting on silicon oxide, there are trapped electric charges inside the silicon oxide in some places, and these induce some charge in the overlying graphene. You get quite a bit of variation in the density of electrons. If graphene sits on boron nitride, the variation is two orders of magnitude less."

In his lab, LeRoy demonstrates the first and surprisingly low-tech step in characterizing the graphene samples: He places a tiny flake of graphite the stuff that makes up pencil "lead" on sticky tape, folds it back on itself and peels it apart again, in a process reminiscent of a Rorschach Test.

"You fold this in half," he explained, "and again, and again, until it gets thin. Graphene wants to peel off into these layers, because the bonds between the atoms in the horizontal layer are strong, but weak between atoms belonging to different layers. When you put this under an optical microscope, there will be regions with one, two, three, four or more layers. Then you just search for single-layer ones using the microscope."

"It's hard to find the sample because it's very, very small," said Jiamin Xue, a doctoral student in LeRoy's lab and the paper's leading author. "Once we find it, we put it between two gold electrodes so we can measure the conductance."

To measure the topography of the graphene surface, the team uses a scanning tunneling microscope, which has an ultrafine tip that can be moved around.

"We move the tip very close to the graphene, until electrons start tunneling to it," Xue explained. "That's how we can see the surface. If there is a bump, the tip moves up a bit."

For the spectroscopic measurement, Xue holds the tip at a fixed distance above the sample. He then changes the voltage and measures how much current flows as a function of that voltage and any given point across the sample. This allows him to map out different energy levels across the sample.

"You want as t
'/>"/>

Contact: Daniel Stolte
stolte@email.arizona.edu
520-626-4402
University of Arizona
Source:Eurekalert  

Page: 1 2 3 4

Related biology technology :

1. New nanoscale transistors allow sensitive probing inside cells
2. New 40th Edition of Grays Anatomy Celebrates 150 Years as the Worlds Preeminent Anatomical Reference
3. University of Helsinki and ASM International renew research agreement on atomic layer deposition
4. New imaging technique reveals the atomic structure of nanocrystals
5. Carbon Design Innovations, Inc. Introduces Carbon Nanotube Probe Technology for Atomic Force Microscopy, CNT-Probes Deliver New Level of AFM Imaging Performance
6. U-M physicists create first atomic-scale map of quantum dots
7. NIST researchers put a new spin on atomic musical chairs
8. NIST researchers holding steady in an atomic-scale tug-of-war
9. Nanotechnologists reveal the frictional characteristics of atomically thin sheets
10. Cold atoms and nanotubes come together in an atomic black hole
11. A little less force: Making atomic force microscopy work for cells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Probing atomic chicken wire
(Date:12/22/2014)... 2014 The Center for Professional ... technical training across the life sciences industry, has partnered ... (SCDM) to provide the organization's members with discounted classroom ... to the more than 350 sessions across 80 course ... off when registering for a public course ...
(Date:12/22/2014)... 22, 2014  Alternative Energy & Environmental Solutions, ... signed a letter of intent to acquire BioTechPharma ... patented a nanotechnology-based development platform used to create ... rapid on-site collection and testing to identify infectious ... in an immediate, non-invasive and cost-effective manner. ...
(Date:12/22/2014)... The American Journal of ... research, reviews and editorials addressing developments and pathways ... published a provocative article exploring the role of ... potential treatment of prostate cancer. , The ... the possibility that there could be a connection ...
(Date:12/19/2014)... Tigard, OR and Hershey, PA (PRWEB) December 19, ... (OTC Pink: BJCT), a leading developer and manufacturer ... has entered into an agreement with Immunomic Therapeutics, ... Bioject’s Biojector®-2000 needle-free injection device with its LAMP™ ... receives an option for an exclusive Worldwide license ...
Breaking Biology Technology:CfPIE Announces Partnership with the Society for Clinical Data Management 2CfPIE Announces Partnership with the Society for Clinical Data Management 3ALNE Announces Intention To Acquire BioTechPharma 2Prostate Cancer Experts Dissect the Role of Follicle-stimulating Hormone in the Development, Progression and Potential Treatment of Prostate Cancer 2Prostate Cancer Experts Dissect the Role of Follicle-stimulating Hormone in the Development, Progression and Potential Treatment of Prostate Cancer 3Prostate Cancer Experts Dissect the Role of Follicle-stimulating Hormone in the Development, Progression and Potential Treatment of Prostate Cancer 4Bioject and Immunomic Therapeutics Enter into an Agreement for License of Needle-Free Technology for LAMP-vax Vaccines 2Bioject and Immunomic Therapeutics Enter into an Agreement for License of Needle-Free Technology for LAMP-vax Vaccines 3
... Dyadic International, Inc. (Pink Sheets: DYAI) ("Dyadic"), a leading-edge early-stage biotechnology ... long-term growth objectives: , , , ... ) , , , ... Anne E. Whitehead as Executive Director of Strategic Alliances . Ms. ...
... Ansell today announced the launch,of their new GAMMEX(R) Powder-Free glove with ... in, Perth, Australia . , , ... It is the first surgical glove which incorporates a proprietary,antimicrobial coating ... in the event of a breach during,surgery. , ...
... INDIANAPOLIS , May 3 ... to our life sciences strengths.  According to a new ... released today at the BIO International Conference in ... with specialized bioscience employment in three of the four ...
Cached Biology Technology:Dyadic International Strengthens Management Team 2Dyadic International Strengthens Management Team 3Dyadic International Strengthens Management Team 4Dyadic International Strengthens Management Team 5Ansell Launches Worlds's First Antimicrobial Surgical Glove 2Indiana Continues to Make Its Mark as a Leading Life Sciences Center 2Indiana Continues to Make Its Mark as a Leading Life Sciences Center 3Indiana Continues to Make Its Mark as a Leading Life Sciences Center 4Indiana Continues to Make Its Mark as a Leading Life Sciences Center 5Indiana Continues to Make Its Mark as a Leading Life Sciences Center 6
(Date:12/10/2014)... 9, 2014 CIE San Diego has launched ... the connective tissue that enhances care coordination among social ... share client-level information; earned a second $1 million grant ... serving seniors aging in community and; will be recognized ... 11 th 4-6p. CIE San Diego ...
(Date:12/4/2014)... GARDENS, Fla. , Dec. 3, 2014 /PRNewswire/ ... solutions, today announced that its DigitalPersona ® ... fingerprint readers have been deployed throughout First Bank ... , South Carolina and ... in Southern Pines, North Carolina ...
(Date:11/21/2014)... Nov. 20, 2014 Strict laws against distracted ... piloting the North American and European automotive sector towards ... gesture recognition systems that are intuitive and able to ... the industry. New analysis from Frost ... Market in Europe and ...
Breaking Biology News(10 mins):Community Information Exchange San Diego Launches Pilot, Secures $1 Million Expansion Grant, and Becomes a "Live Well San Diego" Partner 2Community Information Exchange San Diego Launches Pilot, Secures $1 Million Expansion Grant, and Becomes a "Live Well San Diego" Partner 3Community Information Exchange San Diego Launches Pilot, Secures $1 Million Expansion Grant, and Becomes a "Live Well San Diego" Partner 4First Bank Partners with Crossmatch to Increase Log In Security 2First Bank Partners with Crossmatch to Increase Log In Security 3Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 2Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 3Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 4
... free of charge for all holders of a valid ... access to the onsite press facilities, including a working ... will also be able to assist you in organising ... can register for free online at: http://www.eular.org/congress_press_registration.cfm ...
... researchers at North Carolina State University have found that ... intestinal birth defects may also inhibit the growth and ... chemical compounds created by NC State chemist Dr. Alex ... particular interest to her research: a compound that induced ...
... Indonesia has promised to become a world leader ... committed to a 26% reduction in greenhouse gas emissions ... 14% would have to come from reducing emissions from ... and other bodies are expected to raise total emission ...
Cached Biology News:Compound useful for studying birth defects may also have anti-tumor properties 2Hotspots of carbon confusion in Indonesia threaten to warm the world more quickly 2Hotspots of carbon confusion in Indonesia threaten to warm the world more quickly 3Hotspots of carbon confusion in Indonesia threaten to warm the world more quickly 4Hotspots of carbon confusion in Indonesia threaten to warm the world more quickly 5
... Immunogen: Partially purified chicken intestinal ... vitamin D receptor (VDR) from human, ... fish tissues. This antibody does ... receptors. MA1-710 detects both the ...
Unique enzyme blend containing Taq and Pwo DNA Polymerase and another thermostable enzyme. The Expand 20 kbPLUS PCR System also includes an optimized reaction buffer, MgCl2 solution, and a human cont...
... DNA Polymerase is ideal for high-fidelity ... applications such as cloning and mutagenesis. ... a proprietary enzyme preparation containing recombinant ... proofreading (3'Cut Site5' exonuclease) activity. ...
... supply is a highly compact, extremely reliable and ... knob and one hi-lo range switch control the ... from 20 to 250 volts. One two-position switch ... voltage to output current. For maximum safety, the ...
Biology Products: