Scientists Create Nanodiamonds with Electron Beams

A team of researchers at the University of Tokyo has discovered a new way to make nanodiamonds using electron beams. This method can turn a special molecule called adamantane into tiny diamonds while avoiding much of the damage that electron beams usually cause to organic materials. The breakthrough could open new doors in materials science and electron microscope technology.

Traditionally, man-made diamonds are produced either by using extreme heat and pressure or by growing them with chemical vapor deposition. The new approach is different: it works in a low-pressure environment, where precisely controlled electron beams trigger the conversion of adamantane (C₁₀H₁₆) into nanodiamonds.

Adamantane is well suited for this process because its structure resembles that of a diamond. The transformation requires breaking certain C–H bonds and forming new C–C bonds, which build the three-dimensional diamond lattice. While scientists have long believed this was possible, it had never been clearly demonstrated until now.

Using a transmission electron microscope, the researchers directly watched the process at the atomic level. Under vacuum and low-temperature conditions, they shined electron beams onto adamantane crystals for a few seconds, capturing the entire conversion into nanodiamonds in real time.

The team successfully created nanodiamonds up to 10 nanometers wide, with complete and defect-free crystal structures. Tests also showed that other hydrocarbons could not achieve the same transformation, highlighting adamantane's unique role in this discovery.