- New experiments with diamond nanoneedles show that diamonds can be bend.
- Researches bent diamond pillars (20 nanometers in length) to 90 degrees without breaking.
- These diamond nanopillars can undergo a new form of plastic deformation.
Diamonds are the best-known and most sought-after gemstones. They possess several extraordinary properties — such as the highest hardness and thermal conductivity of any natural material — that make these crystal structures incredibly valuable.
Recently, researchers at the University of Technology Sydney discovered a new property of diamond: it can be bent and deformed at the nanoscale.
Along with opening a wide range of possibilities for the design and engineering of nanoscale devices, this newly discovered property of diamond also illustrates the challenges that lie ahead for future nanotechnologies.
Bending Diamond Nanopillars
Understanding the mechanical deformation and damage tolerances of nanostructured materials is very crucial for applications in defense, sensing, and energy storage.
It has been already proven that mechanical characteristics of bulk materials (including metals and silica glasses) can be altered significantly when their dimensions are reduced to the micro and nanoscale. In this study, researchers tested this phenomenon in diamonds.
Diamond is of a particular scientific and technological interest because it is the front runner for emerging applications in microelectronics, nanophotonics, and radiation shielding systems. It has many uses in quantum information processing, temperature sensing, and medical imaging.
To find out how single-crystal diamonds behave at the nanoscale, researchers experimented with diamond nanoneedles, about 20 nanometers in length. They used the electron beam of a scanning electron microscope to locally charge diamond nanoneedles (also called nanopillars) and their surroundings.
Surprisingly, this created Coulomb forces strong enough to deflect the nanopillars. The technique is quite unique because it doesn’t require physical contact to induce bending.
Using this non-destructive and reversible technique, researchers were able to bend diamond nanopillars from the middle to 90 degrees without breaking. They also demonstrated that these nanopillars could undergo a new form of plastic deformation, which primarily depends on the nanopillar dimensions and crystallographic orientation of the diamond.
Image illustrating the deformation of single-crystal diamond nanopillars | Courtesy of researchers
The findings give significant insights into the dynamics of how nanostructured materials bend and distort and how changing their nanostructure parameters can alter their physical properties (including optical, mechanical, and magnetic properties).
In this new state of carbon (named 08-carbon), the diamond-like bonds progressively break in a zipper-like pattern, exhibiting unprecedented mechanical behavior of diamond.
The potential applications of this nanotechnology are very broad, ranging from improved performance in optomechanics, sensing, and energy generation to the development of better optical filters, capacitors, and air filtration systems.