Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Magical BEANs: New Nano-sized Particles Could Provide Mega-sized Data Storage

The ability of phase-change materials to readily and swiftly transition between different phases has made them valuable as a low-power source of non-volatile or “flash” memory and data storage.

Now an entire new class of phase-change materials has been discovered by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley that could be applied to phase change random access memory (PCM) technologies and possibly optical data storage as well. The new phase-change materials – nanocrystal alloys of a metal and semiconductor – are called “BEANs,” for binary eutectic-alloy nanostructures.

This schematic shows enthalpy curves sketched for the liquid, crystalline and amorphous phases of a new class of nanomaterials called “BEANs” for Binary Eutectic-Alloy Nanostructures. (Image courtesy of Daryl Chrzan)

“Phase changes in BEANs, switching them from crystalline to amorphous and back to crystalline states, can be induced in a matter of nanoseconds by electrical current, laser light or a combination of both,” says Daryl Chrzan, a physicist who holds joint appointments with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Department of Materials Science and Engineering. “Working with germanium tin nanoparticles embedded in silica as our initial BEANs, we were able to stabilize both the solid and amorphous phases and could tune the kinetics of switching between the two simply by altering the composition.”

Chrzan is the corresponding author on a paper reporting the results of this research which has been published in the journal NanoLetters titled “Embedded Binary Eutectic Alloy Nanostructures: A New Class of Phase Change Materials.”

Co-authoring the paper with Chrzan were Swanee Shin, Julian Guzman, Chun-Wei Yuan, Christopher Liao, Cosima Boswell-Koller, Peter Stone, Oscar Dubon, Andrew Minor, Masashi Watanabe, Jeffrey Beeman, Kin Yu, Joel Ager and Eugene Haller.

“What we have shown is that binary eutectic alloy nanostructures, such as quantum dots and nanowires, can serve as phase change materials,” Chrzan says. “The key to the behavior we observed is the embedding of nanostructures within a matrix of nanoscale volumes. The presence of this nanostructure/matrix interface makes possible a rapid cooling that stabilizes the amorphous phase, and also enables us to tune the phase-change material’s transformation kinetics.”

A eutectic alloy is a metallic material that melts at the lowest possible temperature for its mix of constituents. The germanium tin compound is a eutectic alloy that has been considered by the investigators as a prototypical phase-change material because it can exist at room temperature in either a stable crystalline state or a metastable amorphous state. Chrzan and his colleagues found that when germanium tin nanocrystals were embedded within amorphous silica the nanocrystals formed a bilobed nanostructure that was half crystalline metallic and half crystalline semiconductor.

"Rapid cooling following pulsed laser melting stabilizes a metastable, amorphous, compositionally mixed phase state at room temperature, while moderate heating followed by slower cooling returns the nanocrystals to their initial bilobed crystalline state,” Chrzan says. “The silica acts as a small and very clean test tube that confines the nanostructures so that the properties of the BEAN/silica interface are able to dictate the unique phase-change properties.”

While they have not yet directly characterized the electronic transport properties of the bilobed and amorphous BEAN structures, from studies on related systems Chrzan and his colleagues expect that the transport as well as the optical properties of these two structures will be substantially different and that these difference will be tunable through composition alterations.

“In the amorphous alloyed state, we expect the BEAN to display normal, metallic conductivity,” Chrzan says. “In the bilobed state, the BEAN will include one or more Schottky barriers that can be made to function as a diode. For purposes of data storage, the metallic conduction could signify a zero and a Schottky barrier could signify a one.”

Chrzan and his colleagues are now investigating whether BEANs can sustain repeated phase-changes and whether the switching back and forth between the bilobed and amorphous structures can be incorporated into a wire geometry. They also want to model the flow of energy in the system and then use this modeling to tailor the light/current pulses for optimum phase-change properties.

The in-situ Transmission electron microscopy characterizations of the BEAN structures were carried out at Berkeley Lab’s National Center for Electron Microscopy, one of the world’s premier centers for electron microscopy and microcharacterization.

Berkeley Lab is a U.S. Department of Energy (DOE) national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California for the DOE Office of Science. Visit our Website at

Additional Information

For more information on the research of Daryl Chrzan, visit the Website at

For more information on the National Center for Electron Microscopy visit the Website at

Lynn Yarris | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Light-driven atomic rotations excite magnetic waves
24.10.2016 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>