1. Small diamonds: what are they good for? Dr James Rabeau Department of Physics Macquarie University Sydney, Australia 5  m 5 mm 5 cm 50 nm (10 -2 ) (10 -3 ) (10 -6 ) (10 -9 ) April 28, 2010

2. A little bit about scale 1metre = 1 metre 1centimetre = 1/100 metre 1millimetre = 1/1000 metre 1 micrometre= 1/1000000 metre 1 nanometre= 1/1000000000 metre Human hair = 50 micrometres Nanodiamond = 1-50 nanometres (about 1000 times smaller than hair)

3. The biggest big-wig in Australia talks about them!!

4. We can make diamonds!

5. Gaseous Reagents Surface Processes Bulk Processes and Properties REACTANTS SUBSTRATE H 2 + CH 4 Gaseous Processes ACTIVATION e-, heat H 2 2H CH 4 + H CH 3 + H 2 FLOW AND REACTION Diffusion 15 torr H 2 0.1 to 1 % CH 4 800 C, 800 Watts Chemical vapour deposition (CVD) of diamond Jim Butler

6. CVD system used for these experiments (glorified microwave oven) Controls Chamber Magnetron Sample loading Typical conditions: 1.2 kW 40 Torr 500 sccm 0.7% CH 4 / H 2 800 C

7. Microwave CVD of polycrystalline diamond Isolated diamond crystals Nucleation Growth H 2 /CH 4 Continuous diamond film Abrade with diamond powder (<0.25 µm) (combined with other materials…?) 50 nm diamonds µm diamonds +N, B, He …

8. University of Bristol Selective area deposition: -Patterned nucleation or -laser ablation, or other etching of film after deposition. Patterned diamond films

9. High-Pressure High-Temperature

10. CVD Single Crystal diamond Apollo Rose – 4 mm Sumitomo 8 mm NRL Carnegie (5 ct cut from 10ct) Univ. of Paris Courtesy of Jim Butler

11. Nanodiamond powder TEM Other diamond comes in dust or powder form. Used for polishing, cutting tools etc.

12. Why does it matter?

13. Microscopy – seeing small things What colour is sand?

14. What about the human body?

15. Sand grains are pretty big, what if we want to see smaller? n Anything smaller than around 1/2 micron cannot be resolved optically! That means the “grains” of sand would be invisible! n We need different techniques to see them. http://learn.genetics.utah.edu/content/begin/cells/scale/

16. Think of these as nano-light globes If we shine light (laser light) on them, they glow brightly!

17. Bio-Applications – Bio labelling, imaging and tracking n Nanodiamond can be attached to biological objects n They are “biocompatible” n They don’t “bleach” Fu et al. PNAS 104 (2007) Chang et al. Nature Nanotech 3 (2008)

18. Microscopy n So, by attaching nanodiamonds to biological objects, we can SEE more! n We can watch the bright nanodiamonds moving around, and what they do under certain circumstances n Ultimately, we can learn more about the human body, disease, and potential cures.

19. Diamonds in cells

20. Thank you for your attention, and I hope to see you in my physics lectures in a few years! www.physics.mq.edu.au/research/qmapp