Brookhaven Scientists Create a New Nanostructure

June 28, 2005
Brookhaven Scientists Create a New Nanostructure

Scientists from the U.S. Department of Energy's Brookhaven National Laboratory have devised a method to create a new, intriguing nanostructure: ultra-thin, ribbon-like "nanobelts" bound to nanotubes. Their research achieves several "firsts" in the field of nanoscience, the study of materials on the scale of a billionth of a meter. Additionally, the new structure, described in the June 4, 2005, online version of Nano Letters, is likely to have unique electrical and mechanical properties, and may be useful in many developing nanotechnologies.

Image: The nanobelt-creation process. A nanotube (a) is coated with disorganized germanium atoms (b) that crystallize upon heating, resulting in a rigid germanium nanobelt bonded to the nanotube (c).

"We have produced nanobelts that have controllable thicknesses of about two to five nanometers. It is significant work, since the controllability, the thinness, and the methods we used are all new achievements," said Brookhaven materials scientist Wei-Qiang Han, the study's lead researcher. "But, we are most excited about creating a brand-new type of nanostructure."

To "grow" the nanobelts, which are made of the element germanium, Han and his colleagues first deposited nanotubes onto a grid surface made of copper. They used carbon nanotubes initially and later switched to boron-nitride nanotubes, which are very similar to the carbon variety.

Next, they coated the nanotubes with a disorganized, or "amorphous," layer of germanium atoms, which covered only the exposed top halves. The thickness of the layer was monitored with a device that can easily sense a change of just one-tenth of a nanometer.

Finally, they heated the germanium-coated nanotubes to 750 degrees Celsius inside a very powerful microscope. During heating, the amorphous germanium atoms crystallized and, simultaneously, pulled away from the sides of the nanotubes, changing from a curved half-cylinder to a rigid, flat strip about four nanometers thick. The nanobelts remained chemically attached to the nanotubes, resembling, for example, a ruler glued to the side of a cardboard tube.

"This method is much better than other techniques, which typically yield nanobelts more than 10 nanometers thick," said Han. "Achieving smaller thicknesses is important, since thinner nanobelts have physical properties — better conductivity, for example — that are more suitable for applications, such as components in nanoscale electronic circuits. Also, because our nanobelts are bound to nanotubes, they will likely possess different properties than stand-alone nanobelts or nanotubes. We believe this new structure will enable many new advances in nanotechnology."

In future research, Han and his colleagues plan to study the nanostructure's properties, such as its ability to transport electrons. Understanding how the structure conducts will help them determine if it may be used as a component in nano-electronic circuits.

Han's collaborators on this research are Myron Strongin of Brookhaven's Physics Department and Lijun Wu and Yimei Zhu, both of Brookhaven's Center for Functional Nanomaterials. The work was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science.

Related Link: Brookhaven Center for Functional Nanomaterials

Source: Brookhaven National Laboratory

Related Stories

Recommended for you

Deep-learning robot shows grasp of different objects

October 10, 2015

Robot researchers have had much success in getting robots to walk and run; another challenge has persisted for years, and that is getting robots to pick up and hold on to objects successfully. An international workshop on ...

What are white holes?

October 9, 2015

Black holes are created when stars die catastrophically in a supernova. So what in the universe is a white hole?

Horn of Africa drying ever faster as climate warms

October 9, 2015

The Horn of Africa has become increasingly arid in sync with the global and regional warming of the last century and at a rate unprecedented in the last 2,000 years, according to new research led by a University of Arizona ...

Could 'The Day After Tomorrow' happen?

October 9, 2015

A researcher from the University of Southampton has produced a scientific study of the climate scenario featured in the disaster movie 'The Day After Tomorrow'.

A mission to a metal world—The Psyche mission

October 9, 2015

In their drive to set exploration goals for the future, NASA's Discovery Program put out the call for proposals for their thirteenth Discovery mission in February 2014. After reviewing the 27 initial proposals, a panel of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.