New nanowire growth mechanism observed

May 9, 2014
New nanowire growth mechanism observed
Schematic showing the movement of molten barium-rich nanoparticles to the surface of an yttrium- and copper-rich matrix. The transmission electron microscope image confirms that this leads to outgrowth of yttrium barium copper oxide nanowires via the microcrucible mechanism.

( —A mechanism of growth of anisotropic metal oxides that was predicted 20 years ago has been observed for the first time by researchers at the University of Bristol. The work is described in an article published this week in Science.

The fabrication of nanowires of ternary and quaternary functional materials has become an important goal for their application in miniaturized circuits as diodes and transistors, coaxial gates and sensors.

The growth mechanisms are complex however and invariably proceed via a vapour-liquid-solid process which results in nanowires with a tapering morphology. A nanowire that tapers is undesirable for applications, as functionality would vary along the length, and perhaps even vanish, once a critical size was reached.

Dr Simon Hall and Rebecca Boston in the School of Chemistry, along with colleagues in the University of Birmingham and the National Institute for Materials Science in Tsukuba, Japan have successfully grown of a phase of the superconductor yttrium barium copper oxide that have a constant cross-sectional area.

In doing so, they engineered their syntheses to proceed via the so-called 'microcrucible mechanism' of crystal growth. This was first proposed to account for the growth of certain macroscopic metal oxide whiskers in 1994, but has never been observed at any length scale until now.

The team achieved the first observation of this by using a high-resolution transmission electron microscope with video capture and an in-situ furnace. This enabled them to directly observe molten nanoparticles of barium carbonate migrating through a porous yttrium and copper-rich matrix, catalysing nanowire outgrowth from nano-sized microcrucibles on reaching the surface.

Dr Simon Hall said: "Nanowires produced in this way will have the same physical properties along their entire length, leading to more uniform current-carrying ability, ferroic behaviour and tensile strength.

"This work could pave the way for the next generation of devices that use new, high-performance as their key component."

Explore further: Scientists investigate atomic-scale mechanisms of nanowire growth process

More information: "In Situ TEM Observation of a Microcrucible Mechanism of Nanowire Growth," Rebecca Boston, Zoe Schnepp, Yoshihiro Nemoto, Yoshio Sakka, Simon R. Hall. Science 9 May 2014: Vol. 344 no. 6184 pp. 623-626. DOI: 10.1126/science.1251594

Related Stories

The science of sculpture, nano-style

June 14, 2013

( —The next breakthrough in highly efficient battery technologies and solar cells may very well be nanoscopic crystals of silicon assembled like skyscrapers on wafer-scale substrates. An important route for growth ...

Copper nanowires could become basis for new solar cells

April 26, 2014

( —By looking at a piece of material in cross section, Washington University in St. Louis engineer Parag Banerjee, PhD, and his team discovered how copper sprouts grass-like nanowires that could one day be made ...

Recommended for you

Graphene is strong, but is it tough?

February 4, 2016

Graphene, a material consisting of a single layer of carbon atoms, has been touted as the strongest material known to exist, 200 times stronger than steel, lighter than paper, and with extraordinary mechanical and electrical ...

A new way to make higher quality bilayer graphene

February 8, 2016

(—A team of researchers with members from institutions in the U.S., Korea and China has developed a new way to make bilayer graphene that is higher in quality than that produced through any other known process. ...

Nanoparticle ink could combat counterfeiting

February 5, 2016

(—Researchers have demonstrated that transparent ink containing gold, silver, and magnetic nanoparticles can be easily screen-printed onto various types of paper, with the nanoparticles being so small that they ...

Tiniest spin devices becoming more stable

February 3, 2016

(—In 2011, the research group of Roland Wiesendanger, Physics Professor at the University of Hamburg in Germany, fabricated a spin-based logic device using the spins of single atoms, a feat that represents the ...


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.