Raleigh, North Carolina – Researchers from North Carolina State University have developed a technique to make diamond-related structures. The results were published in the Journal of Applied Physics.
The new form of carbon structure is called Q-carbon and it is not exactly as the diamond we are familiar with. It is harder than diamonds; it’s a lot tighter and smaller; it glows when it’s exposed to low energy levels; it is ferromagnetic, which is not present in other solid carbon forms; and it can be made in a laboratory at room temperature with the air pressure in ambient atmospheric. Actually, the researchers suggest that it’s unlikely to occur in the natural world.
To create this laboratory-made diamond-like structure, researchers start with a substrate, such as sapphire, glass or a plastic polymer. The substrate is then coated with amorphous carbon, an elemental carbon that, unlike graphite or diamond, does not have a regular, well-defined crystalline structure.
The carbon is then hit with a single laser pulse which lasts approximately 200 nanoseconds. During this pulse, the temperature of the carbon is raised to 4,000 Kelvin (or around 3,727 degrees Celsius) then, it is rapidly cooled down. This operation takes place at one atmosphere, the same pressure as the surrounding air. The end result is a film of Q-carbon.
By modifying the production technique and changing how quickly the laser pulse heats and cools the carbon, the team can create diamond structures at room temperature and pressure. On the contrary, synthetic diamond generally requires huge pressures during its formation.
“We can create a diamond in the form of a nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling,” scientists wrote in the study.
Professor Jay Narayan at North Carolina State said that Q-carbon could prove to be a promising material for creating new electronic displays because of its strength and ability to release electrons. This solid carbon state can also be utilized for the production of single-crystal diamond materials.
Source: AIP Scitation