Unbreakable material nearly as hard as diamond, with high energy density

Amazing stuff! A possible breakthrough! 

"... a breakthrough, synthesizing carbon and nitrogen precursors to create carbon nitrides, which are tougher than cubic boron nitride – currently the second hardest material behind diamond. ...

While scientists recognized the potential of carbon nitrides back in the 1980s, including their high heat resistance, creating them was another story. In fact, no credible studies into their synthesis have been produced – until now. ..."

"... The breakthrough opens doors for multifunctional materials to be used for industrial purposes including protective coatings for cars and spaceships, high-endurance cutting tools, solar panels and photodetectors, experts say. ...

The team subjected various forms of carbon nitrogen precursors to pressures of between 70 and 135 gigapascals – around one million times our atmospheric pressure – while heating it to temperatures of more than one and a half thousand degrees celsius.  

To identify the atomic arrangement of the compounds under these conditions, the samples were illuminated by an intense X-ray beam at three particle accelerators – the European Synchrotron Research Facility in France, the Deutsches Elektronen-Synchrotron in Germany and the Advanced Photon Source based in the United States. ..."

From the abstract:

"Carbon nitrides featuring three-dimensional frameworks of CN4 tetrahedra are one of the great aspirations of materials science, expected to have a hardness greater than or comparable to diamond. After more than three decades of efforts to synthesize them, no unambiguous evidence of their existence has been delivered. Here, the high-pressure high-temperature synthesis of three carbon-nitrogen compounds, tI14-C3N4, hP126-C3N4, and tI24-CN2, in laser-heated diamond anvil cells, is reported. Their structures are solved and refined using synchrotron single-crystal X-ray diffraction. Physical properties investigations show that these strongly covalently bonded materials, ultra-incompressible and superhard, also possess high energy density, piezoelectric, and photoluminescence properties. The novel carbon nitrides are unique among high-pressure materials, as being produced above 100 GPa they are recoverable in air at ambient conditions."

Unbreakable material nearly as hard as diamond, with high energy density It’s taken more than three decades, but scientists believe they have created a material that’s almost impossible to break and could rival diamond as the hardest substance on the planet.

Ultra-hard material to rival diamond discovered Scientists have solved a decades-long puzzle and unveiled a near unbreakable substance that could rival diamond, as the hardest material on earth, a study says.

Synthesis of Ultra-Incompressible and Recoverable Carbon Nitrides Featuring CN4 Tetrahedra (open access)

Crystal structures of tI14-C3N4 and hP126-C3N4 at 124 GPa.