Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Next scientific fashion could be designer nanocrystals



Prof. David Mazziotti (above) and colleagues Dmitri Talapin and Greg Engel are attempting to formulate the basic principles needed to improve the efficiency and information transfer of electrons in nanocrystals. “That kind of thing you can play into many applications,” said Mazziotii.
Photo by Lloyd DeGrane
Prof. David Mazziotti (above) and colleagues Dmitri Talapin and Greg Engel are attempting to formulate the basic principles needed to improve the efficiency and information transfer of electrons in nanocrystals. “That kind of thing you can play into many applications,” said Mazziotii.

Photo by Lloyd DeGrane

Abstract:
Three University of Chicago chemistry professors hope that their separate research trajectories will converge to create a new way of assembling what they call "designer atoms" into materials with a broad array of potentially useful properties and functions.

Next scientific fashion could be designer nanocrystals

Chicago, IL | Posted on December 11th, 2012

These "designer atoms" would be nanocrystals—crystalline arrays of atoms intended to be manipulated in ways that go beyond standard uses of atoms in the periodic table. Such arrays would be suited to address challenges in solar energy, quantum computing and functional materials.

The partners in the project are Prof. David Mazziotti, and Associate Professors Greg Engel and Dmitri Talapin. All three have made key advances that are critical for moving the project forward. Now, with $1 million in funding from the W. M. Keck Foundation, they can build on their separate advances in a concerted way toward a new goal.

"If you look at the history of science, a major development starts with people of different backgrounds talking to each other and learning from each other and doing something really revolutionary rather than incremental," Talapin said.

Developments in Talapin's laboratory form the core of the project. A synthetic inorganic chemist, he specializes in creating precisely engineered nanocrystals with well-defined characteristics.

Nanocrystals consist of hundreds or thousands of atoms. This is small enough that new quantum phenomena begin to emerge, but large enough to provide convenient "modules" for the design of new materials. "It's an interesting combination in that you build materials not from individual atoms, but from the units that resemble atoms in many ways but also behave as a metal, semiconductor or magnet. It's a bit crazy," Talapin said.

The potential of the new arrangements may exceed that of existing elements. Chemists cannot tune the properties of hydrogen or helium, for example, but they can tune the properties of nanocrystals.

"You build chemistry from atoms, and quantum mechanics provides principles for doing that," said Mazziotti, referring to the laws of physics that dominate the world at ultra-small scales. "In the same way, we envision tremendous opportunities in terms of taking nanocrystalline arrays and nanocrystals as the building blocks for new structures where we assemble them into strongly correlated systems."
Nanocrystalline building blocks

The essence of strong correlation, of chemical bonds, of chemistry generally, is the connections between particles and how properties of these particles change as they bind to one another, Engel noted. "It's about new emerging properties coming from strong mixing between the electronic states of particles, the same way two atoms come together to make a molecule," he said.

Hydrogen and oxygen gases have very different properties. Yet when two hydrogen atoms share electrons with an oxygen atom, they form water. The UChicago trio's ambition is to extend this framework from the level of individual atoms to the level of small, functional objects, such as metal or magnetic semiconductors.

The key to their project is controlling the degree of correlation between electrons on different nanocrystals. In 2009, Talapin and his collaborators developed a way to control the motions of electrons as they move from one nanocrystal to the next. Their "electronic glue" enables semiconductor nanocrystals to efficiently transfer their electric charges to one another, an important step in the synthesis of new materials.

"That glue is provided by a special tuning of the behavior of the electrons," Mazziotti said. "You want the electrons to have their motions correlated in a special way to allow the efficient transfer of that energy from one nanocrystal to the other."

Achieving greater control of correlated electrons—those whose motions are linked to each other—on different nanocrystals is the key to success in the Keck project.

"If we can enhance that, then we can essentially develop a whole palette of new materials that essentially derives from using the nanocrystals as building blocks and strong correlation as a way of tuning, essentially, the degree to which or how they talk to each other," Mazziotti said. "We want really efficient transfer of energy and information between the different units. Previously in the area of nanocrystalline arrays, the nanocrystals only communicated with each other very weakly."
Developing a new palette

Mazziotti and Engel bring theoretical and spectroscopic advances, respectively, to the collaboration. Mazziotti's advance provides an alternative to traditional approaches to computing strongly correlated electrons in molecules, which scale exponentially with the number of electrons. He has solved a longstanding problem that enables calculations using just two of a molecule's electrons, which dramatically decreases the computational cost.

His studies of firefly bioluminescence and other phenomena have shown that as molecular systems grow larger, strong correlations between electrons grow more powerful and open new possibilities for emergent behavior. In the context of a semiconducting material such as silicon, emergent behavior is how individual nanoparticles effectively lose their identity, giving rise to collective properties in new materials.

"As the size of a molecular system increases, we see the emergence of new physics behavior and the importance of strong correlation of electrons," Mazziotti said. "The importance of strong correlation increases dramatically with system size."

The advance in Engel's research group was the development of a technique called GRadient-Assisted Photon Echo (GRAPE) spectroscopy, which borrows ideas from magnetic resonance imaging but is used for spectroscopy rather than medical imaging. Engel already has used GRAPE to observe the correlated motion and coupling between chromophores, which are light-absorbing molecules. Now he will apply the technique to nanocrystals.

"This, for the first time, will let us really see the direct nature of the electronic coupling that's at the heart of this idea of new bonding concepts in designer atoms," Engel said. "We'll be able to provide the experimental evidence that will combine the theory that David is developing with the new structures that Dmitri is building."

Based in Los Angeles, the W. M. Keck Foundation was established in 1954 by the late W. M. Keck, founder of the Superior Oil Company. The foundation's grant making is focused primarily on pioneering efforts in medical research, science and engineering. The foundation also maintains a program to support undergraduate science and humanities education and a Southern California Grant Program that provides support in health care, civic and community services, education and the arts, with a special emphasis on children.

By Steve Koppes

####

For more information, please click here

Contacts:
Steve Koppes
News Officer for Physical Sciences
News Office, University Communications

(773) 702-8366

Copyright © University of Chicago

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

New drug-delivery approach holds potential for treating obesity May 2nd, 2016

Spintronics for future information technologies: Spin currents in topological insulators controlled May 2nd, 2016

Nanoparticles present sustainable way to grow food crops May 1st, 2016

Searching for a nanotech self-organizing principle May 1st, 2016

Physics

Superfast light source made from artificial atom April 28th, 2016

The atom without properties April 22nd, 2016

Imaging

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

Bruker Introduces First of Its Kind Dimensional Analysis System: The Novel Contour CMM™ System Fully Integrates 3D Coordinate Measurements with Nanoscale Surface Height, Texture, Waviness and Form Characterization April 26th, 2016

Bruker Introduces Dimension FastScan Pro Industrial AFM: Providing Nanometer-Resolution at High Scan Rates for up to 300-mm Samples April 26th, 2016

Chemistry

Adding some salt to the recipe for energy storage materials: Researchers use common table salt as growth template April 22nd, 2016

NRL reveals novel uniform coating process of p-ALD April 21st, 2016

Team builds first quantum cascade laser on silicon: Eliminates the need for an external light source for mid-infrared silicon photonic devices or photonic circuits April 21st, 2016

Discoveries

New drug-delivery approach holds potential for treating obesity May 2nd, 2016

Spintronics for future information technologies: Spin currents in topological insulators controlled May 2nd, 2016

Nanoparticles present sustainable way to grow food crops May 1st, 2016

Clay nanotube-biopolymer composite scaffolds for tissue engineering May 1st, 2016

Materials/Metamaterials

Clay nanotube-biopolymer composite scaffolds for tissue engineering May 1st, 2016

Exploring phosphorene, a promising new material April 29th, 2016

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Announcements

New drug-delivery approach holds potential for treating obesity May 2nd, 2016

Spintronics for future information technologies: Spin currents in topological insulators controlled May 2nd, 2016

Nanoparticles present sustainable way to grow food crops May 1st, 2016

Clay nanotube-biopolymer composite scaffolds for tissue engineering May 1st, 2016

Tools

Exploring phosphorene, a promising new material April 29th, 2016

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

Chemists use DNA to build the world's tiniest thermometer April 27th, 2016

Bruker Introduces Dimension FastScan Pro Industrial AFM: Providing Nanometer-Resolution at High Scan Rates for up to 300-mm Samples April 26th, 2016

Energy

Nanoparticles present sustainable way to grow food crops May 1st, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Flipping a chemical switch helps perovskite solar cells beat the heat April 26th, 2016

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Brookhaven's Oleg Gang Named a Battelle 'Inventor of the Year': Recognized for work using DNA to guide and regulate the self-assembly of nanoparticles into clusters and arrays with controllable properties April 25th, 2016

Zip software can detect the quantum-classical boundary: Compression of experimental data reveals the presence of quantum correlations April 21st, 2016

Making electronics out of coal: Instead of burning up this complex hydrocarbon, let's make devices from it April 20th, 2016

Nano-magnets produce 3-dimensional images: Wide-view 3-dimensional holographic display composed of nano-magnetic pixels April 20th, 2016

Solar/Photovoltaic

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Flipping a chemical switch helps perovskite solar cells beat the heat April 26th, 2016

Manipulating light inside opaque layers April 24th, 2016

Thin-film solar cells: How defects appear and disappear in CIGSe cells: Concentration of copper plays a crucial role April 23rd, 2016

Quantum nanoscience

The atom without properties April 22nd, 2016

Changing the color of single photons in a diamond quantum memory April 7th, 2016

New state of matter detected in a two-dimensional material April 6th, 2016

Scientists divide magnetic vortices into collectivists and individualists April 3rd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic