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Small diamonds: what are they good for?

Small diamonds: what are they good for?. 50 nm. Dr James Rabeau Department of Physics Macquarie University Sydney, Australia. (10 -9 ). (10 -2 ). (10 -3 ). (10 -6 ). 5 mm. 5 m m. 5 cm. April 28, 2010. A little bit about scale. 1metre = 1 metre 1centimetre = 1/100 metre

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Small diamonds: what are they good for?

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  1. Small diamonds: what are they good for? 50 nm Dr James RabeauDepartment of PhysicsMacquarie UniversitySydney, Australia (10-9) (10-2) (10-3) (10-6) 5 mm 5 mm 5 cm 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. 15 torr H2 0.1 to 1 % CH4 800 C, 800 Watts Chemical vapour deposition (CVD) of diamond Gaseous Reagents REACTANTS H2 + CH4 ACTIVATION Gaseous Processes e-, heat H2 2H CH4 + H CH3 + H2 Surface Processes FLOW AND REACTION Diffusion Bulk Processes and Properties SUBSTRATE Jim Butler

  6. CVD system used for these experiments (glorified microwave oven) Magnetron Chamber Typical conditions: 1.2 kW 40 Torr 500 sccm 0.7% CH4 / H2 800 C Controls Sample loading

  7. Microwave CVD of polycrystalline diamond +N, B, He … Growth Nucleation H2/CH4 Abrade with diamond powder (<0.25 µm) (combined with other materials…?) Continuous diamond film Isolated diamond crystals µm diamonds 50 nm diamonds

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

  9. High-Pressure High-Temperature

  10. CVD Single Crystal diamond Carnegie (5 ct cut from 10ct) Univ. of Paris NRL Apollo Rose – 4 mm Sumitomo 8 mm 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? • Anything smaller than around 1/2 micron cannot be resolved optically! That means the “grains” of sand would be invisible! • 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 • Nanodiamond can be attached to biological objects • They are “biocompatible” • They don’t “bleach” Fu et al. PNAS 104 (2007) Chang et al. Nature Nanotech 3 (2008)

  18. Microscopy • So, by attaching nanodiamonds to biological objects, we can SEE more! • We can watch the bright nanodiamonds moving around, and what they do under certain circumstances • 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

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