The findings of their work have just been published in a paper entitled “Evolutionary search for superhard materials: Methodology and applications to forms of carbon and TiO2,” in the current online edition of Physical Review B.
Superhard materials, used in many scientific and technological applications (for example as abrasive coatings in cutting and drilling tools), are a relatively small class of compounds. The most famous and widely used of these are diamond and cubic boron nitride. However, both of them are unstable at high temperatures, which limit their applicability. Therefore, the search for new superhard compounds is of great interest. Despite numerous efforts, progress has been slow. “The traditional trial-and-error approach to search for new materials usually involves a lot of pain and little gain,” explained Prof. Oganov.
Dr. Lyakhov and Prof. Oganov propose to use supercomputers in the search for new superhard materials. Scientists developed a special hybrid evolutionary algorithm, and tested it on a few promising systems, such as carbon and carbon nitride (which many scientists believe to be able to surpass the diamond by hardness). The results show the power of this algorithm and confirm that diamond is the hardest form of carbon and, so far, the hardest material. As a byproduct of the calculations, a set of novel superhard carbon structures was obtained – these are only marginally softer than diamond. It was also shown that carbon nitride cannot be harder than diamond.
Another area where the algorithm can be used is the validation of controversial experimental data. Researchers give an example by dethroning TiO2 as the hardest known oxide. The suggestion that a high-pressure form of TiO2 is the hardest oxide was made by Swedish researchers in a highly-cited paper published in 2001 in Nature. However, calculations show that all possible forms of TiO2 are much softer than common corundum, Al2O3, and therefore the experimental data from 2001 has to be reconsidered. The latest experiments done at Yale University and the University of Tokyo point in the same direction. In the near future, scientists plan to apply their algorithm to promising systems, such as boron-carbon-oxygen compounds, to search for new superhard materials.
The value of this work goes well beyond the field of superhard materials. The optimization of hardness is a successful proof-of-principle example, which opens the way for a novel computational technique. “A new era in material design and discovery is about to begin,” said Prof. Oganov. “New materials with desired properties will be routinely discovered using supercomputers, instead of the expensive trial-and-error method that is used today.”
| Newswise Science News
Electron tomography technique leads to 3-D reconstructions at the nanoscale
24.05.2018 | The Optical Society
These could revolutionize the world
24.05.2018 | Vanderbilt University
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences