Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material
Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material.
The new technique could lead to the simple creation and manufacture of superconductors or high-efficiency solar cells and light sensors, said leader of the research, Professor Andrei Rode, from The Australian National University (ANU).
"We've created two entirely new crystal arrangements, or phases, in silicon and seen indications of potentially four more," said Professor Rode, a laser physicist at the ANU Research School of Physics and Engineering (RSPE).
"Theory predicts these materials could have very interesting electronic properties, such as an altered band gap, and possibly superconductivity if properly doped"
By focusing lasers onto silicon buried under a clear layer of silicon dioxide, the group have perfected a way to reliably blast tiny cavities in the solid silicon. This creates extremely high pressure around the explosion site and forms the new phases.
The phases have complex structures, which took the team of physicists from ANU and University College London a year to understand.
Using a combination of electron diffraction patterns and structure predictions, the team discovered the new materials have crystal structures that repeat every 12, 16 or 32 atoms respectively, said Professor Jim Williams, from the Electronic Material Engineering group at RSPE.
"The micro-explosions change silicon's simplicity to much more complex structures, which opens up possibility for unusual and unexpected properties," he said.
These complex phases are often unstable, but the small size of the structures means the materials cool very quickly and solidify before they can decay, said Professor Eugene Gamaly, also from the ANU Research School of Physics and Engineering. The new crystal structures have survived for more than a year now.
"These new discoveries are not an accident, they are guided by a deep understanding of how lasers interact with matter," he said.
Conventional methods for creating materials with high pressure use tiny diamond anvils to poke or squeeze materials. However, the ultra-short laser micro-explosion creates pressures many times higher than the strength of diamond crystal can produce.
The team's new method promises a much cheaper and industrially-friendly method for large scale manufacturing of these exotic materials, says Dr Jodie Bradby, also from ANU Research School of Physics and Engineering.
"We reliably create thousands of micron-size modified zones in normal silicon within a second," she said.
"The semiconductor industry is a multi-billion dollar operation - even a small change in the position of a few silicon atoms has the potential to have a major impact."
Andrei Rode | EurekAlert!
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences