Diamond may be the strongest known natural material, but researchers have just entered a fierce competition.
By firing a dime-sized graphite disc on the wall at a speed of 15,000 mph (24,100 km/h), the scientists instantly created a hexagonal diamond that is harder and stronger than natural cubic diamonds. .
Hexagonal diamonds (also known as Lonsdaleite diamonds) are a special type of diamond with carbon Atomic number Arranged in a hexagonal pattern. For a long time, this rare material has been theoretically believed to be stronger than ordinary cubic diamond. It is formed by graphite under extreme high temperature and high stress (for example, at the site of a meteor impact).
However, because the hexagonal diamond found in the impact crater contains too many impurities, scientists have never accurately measured its properties.
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Now, researchers have not only forged hexagonal diamonds, but also combined sound waves and lasers to measure their stiffness—the ability to resist deformation when they are flattened or stretched.
Yogendra Gupta, director of the Institute of Shock Physics at Washington State University, and co-author of the study, said: “Diamond is a very unique material.” Said in a statement. “It is not only the strongest, but also has beautiful optical properties and high thermal conductivity. Now, we have manufactured hexagonal diamonds produced under impact compression experiments, which are much harder than ordinary diamonds.”
Cubic diamonds are usually formed 90 miles (150 kilometers) below the surface of the earth, under pressure many times the depth of deep sea crushing, and temperatures exceeding 2,732 degrees Fahrenheit (1,500 degrees Celsius). But in order to form a hexagonal diamond, the researchers simulated the high-energy impact of a meteor impact, using gunpowder and compressed air to launch a graphite disk at an alarming rate. When the disc hits the wall, the impact wave quickly transforms the disc into a hexagonal diamond shape.
To measure the strength and stiffness of the diamond in less than a second before crushing the mineral to the blacksmith’s shop, the researchers emitted sound waves and used a laser to measure the speed of the sound waves through the hexagonal diamond. (Sound waves can cause diamond density to fluctuate during movement, which affects the path length of the laser beam.) The harder the material, the faster the sound passes through it.
It is difficult to tell whether a hexagonal diamond is harder than a regular diamond. Hardness is a measure of how easy it is to scratch the surface of a material, and the existence of hexagonal diamonds is not long enough for scientists to scratch them.
Currently, scientists have not found a way to make more long-lived hexagonal diamonds in the laboratory, but if a method is discovered, researchers expect them to be versatile-from more effective drill tips to more high-end engagement rings.
Gupta said: “If one day we can produce and polish them, I think they will be more popular than cubic diamonds.” “If someone says to you,’Look, I will choose two diamonds for you: one The other is much rarer. “Which one would you choose?”
The researchers published their findings in the Journal on March 31 Physical Examination B.
Originally published in “Life Science”.