Team introduces novel method to grow elastic diamonds

May 28, 2018, Ulsan National Institute of Science and Technology
UNIST introduces novel method to grow elastic diamonds
Ultralarge and reversible elastic deformation. Credit: MIT

Diamond is the strongest naturally occurring material on Earth. It is also renowned for its high stiffness, exceptional thermal conductivity, high chemical resistance, and high optical transparency. Although these remarkable properties make diamond highly desirable for scientific and technological applications, progress has been slow due to its brittleness.

A recent study involving UNIST has determined that brittle can be bent and stretched elastically when made into ultrafine needles.

This breakthrough has been jointly conducted by Distinguished Professor Feng Ding's team from the Center for Multidimensional Carbon Materials (CMCM), within the Institute for Basic Science (IBS) at UNIST, in collaboration with an international team of researchers from Massachusetts Institute of Technology (MIT), City University of Hong Kong, and Nanyang Technological University. The results of the study has been reported in Science.

The team demonstrated that their nanoscale diamond needles could flex and stretch by as much as 9 percent without breaking, and return to their original shape. Their discovery completely overturns previous findings of diamond brittleness. Their results could open up unprecedented possibilities for tuning its optical, optomechanical, magnetic, phononic, and catalytic properties through elastic strain engineering.

"Ultrahigh elasticity of diamond is due to the paucity of internal defects."

Ordinary diamond in bulk form has a limit of well below one percent stretch, according to the researchers. In the study, Professor Ming's group handled the chemical calculation and the analysis of the crystal structure of diamond and ascribed that the ultrahigh elasticity of the diamond nanoneedles is due to the paucity of internal defects and the relatively smooth surface.

Nanoscale diamond needles, developed by the research team from the City University of Hong Kong. Credit: UNIST
"Diamonds, either natural or artificial, have internal defects in their crystal structure," says Professor Ding. "When outside force is applied to these defects, they can crack and eventually break."

In the study, via detailed simulations, Professor Ding determined precisely how much stress and strain the diamond needles could accommodate without breaking. He determined the corresponding maximum local stress was close to the known theoretical limit achievable with a perfect, defect-free diamond. He noted that defect-free diamonds can stretch by as much as 12 percent without breaking.

"Diamond needles stretched and flexed as much as 9 percent without any breakage."

The research team from the City University of Hong Kong succeeded in fabricating nanoscale diamond needles by plasma-induced etching of diamond thin films deposited on Si substrates through bias-assisted chemical vapor deposition (CVD). As a result, the team was able to demonstrate ultralarge, fully reversible elastic deformation of nanoscale (~300 nanometers) single-crystalline and polycrystalline diamond needles.

The team measured the bending of the diamond needles, which were grown through a process and then etched to their final shape, by observing them in a scanning electron microscope while pressing down on the needles with a standard nanoindenter diamond tip. They demonstrated experimentally that single-crystalline needles are simultaneously ultrastrong and susceptible to large elastic deformation, with fully reversible mechanical deformability of up to a maximum of 9 percent of elastic tensile strain.

The research team expects that their findings could lead to performance enhancement in applications, involving bioimaging and biosensing, strain-mediated nanomechanical resonators, drug delivery, data storage, and optomechanical devices, as well as ultrastrength nanostructures. Besides, Professor Ding noted that large elastic deformation in nanoscale diamond needles will be suitable for use in next-generation flexible and foldable displays.

Explore further: Diamond can turn flexible when made into ultrafine needles, researchers find

More information: Amit Banerjee et al, Ultralarge elastic deformation of nanoscale diamond, Science (2018). DOI: 10.1126/science.aar4165

Related Stories

Physicists stretch diamond using an electric field

December 7, 2017

A research team from the Faculty of Physics of Lomonosov Moscow State University stretched acicular diamond crystallites using an electric field. Deformation occurring during the stretching causes changes in the luminescence ...

Deducing the properties of a new form of diamond

November 30, 2017

Earlier this year, amorphous diamond was synthesized for the first time using a technique involving high pressures, moderately high temperatures and a tiny amount of glassy carbon as starting material. A father-son team at ...

Recommended for you

Compelling evidence for small drops of perfect fluid

December 10, 2018

Nuclear physicists analyzing data from the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC)—a U.S. Department of Energy (DOE) Office of Science user facility for nuclear physics research at Brookhaven National ...

Supercomputers without waste heat

December 10, 2018

Generally speaking, magnetism and the lossless flow of electrical current ("superconductivity") are competing phenomena that cannot coexist in the same sample. However, for building supercomputers, synergetically combining ...

Engineers invent groundbreaking spin-based memory device

December 7, 2018

A team of international researchers led by engineers from the National University of Singapore (NUS) have invented a new magnetic device to manipulate digital information 20 times more efficiently and with 10 times more stability ...

Multichannel vectorial holographic display and encryption

December 7, 2018

Holography is a powerful tool that can reconstruct wavefronts of light and combine the fundamental wave properties of amplitude, phase, polarization, wave vector and frequency. Smart multiplexing techniques (multiple signal ...

0 comments

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.