Chinese researchers mixed hundreds of nanodiamonds in a vacuum and uncovered the reason for their loss of hardness

Chinese researchers uncover the mystery of “loss of stiffness” in nanodiamonds

*During the experiment it was found why diamonds sized from 4 to 12 nm (hundreds of times smaller than a virus) become less elastic and compress more easily.*

What was done
- Experiment

- 100 nanodiamonds were clamped between two cylinders, each with a diamond tip.

- The system was connected to a force sensor and microscope to measure resistance to compression.

- Work was carried out in vacuum to eliminate external influences.

- Modeling

- The obtained data were compared with computer models of the atomic structure of crystals.

Key conclusion
- As size decreases, the proportion of atoms on the surface (shell) increases.

- Connections between the shell and core in nanodiamonds are weaker than in larger stones.

- Therefore small crystals compress more easily: their resistance drops by about 30 % compared with large diamonds.

Why it matters
- Nanomaterials are a key component of future technologies: quantum computers, ultra‑fast sensors, and secure communications.

- Availability: artificial nanodiamonds today cost significantly less, opening new possibilities for their use.

> “Diamonds of ordinary size are known for their exceptional hardness, but at the nanoscale everything changes,” notes lead researcher Chunxin Shan from Zhengzhou University.

> “We have shown that it is precisely the atomic structure of the surface that accounts for the reduction in elasticity.”

Bottom line: The smaller the nanodiamond, the more pronounced the role of surface atoms and the weaker their bonds to the core, leading to a noticeable drop in hardness. This discovery will help optimize the use of nanodiamonds in high‑technology devices.