Recent content by mikegem

Typical film structure put down on diamond to enable solder attachment is Ti/Pt/Au. The Ti reactively bonds with the diamond surface, the Pt prevents inter diffusion, and the Au makes a good bond with solder. There's some work with Cr as the first layer on diamond. It forms a carbide, so...

Nd magnets in freezer Yes, you can store them in a freezer. This will be no different from storing them at room temperature with respect to their losing their magnetic strength over time. Nd:Fe:B magnets have different Curie temperatures depending on their specific formulation. The ones with...

@YummyFur - One of the fun events in my career as a diamond CVD critter involved getting my wife a diamond for her engagement ring. This was years ago, before I and others had shown that you can use CVD methods to make single-crystal diamonds of gem size and quality. I was pretty sure I...

I can recommend a couple of papers for you. One is a 2011 review of diamond CVD technologies, including combustion synthesis. The other is a 2004 paper on increasing the surface area of combustion-deposited diamond films by scanning the flame over the substrate. They might have some details...

Hi - Replying to an email alert I received of your posting. I don't routinely check this board. I would try graphite with a thickness 5mm or greater. This will do two things: first, it will provide good lateral heat transfer, which will tend to reduce the peak temperature (the "hot spot"...

Aluminum carbide is a thermodynamically stable compound in that it occupies a lower energy level than the aluminum and carbon reactants from which it forms, or the reaction would not proceed. Aluminum carbide is a thermodynamically unstable compound with respect to the potential reaction...

I think it does. Please see http://en.wikipedia.org/wiki/Aluminium_carbide The formation of aluminum carbide suggests why carbon nanotubes (probably the MWNT types) might be a superior reinforcing fiber for aluminum due to the potential for high interface strength between the fibers and the...

That's the strange thing about diamond chemical vapor depositon processes - they make diamond even under conditions in which graphite is the more stable carbon species. What happens in general is that carbon atoms that do form graphite react with the surrounding gases and get converted back to...

And I forgot to answer your specific points; 1. Oxygen and acetylene, no other gases needed. People have tried methane/oxygen, ethylene/oxygen and methylacetylene/oxygen but none of these works nearly as well as acetylene/oxygen. It's probably the very high flame temperature that results...

Hi - I have over 25 years of experience in diamond synthesis by various deposition methods, including flame deposition. This is a project that you can do. The BBC reporter is using a welding torch, fueled by oxygen and acetylene, the normal gases used for welding steel with a torch. You do...

One more thought - The impactor method does actually work, it's just that the impactor has to be really big, moving very fast. Diamond particles are routinely found at meteorite impact sites, where they're created in the extreme pressures and temperatures produced when something traveling a few...

I agree you'll have a kinetics problem. To transform graphite to diamond, you need to heat the graphite (gives the energy needed to overcome a potential energy barrier in rearranging sp2 (graphitic) carbon bonds to sp3 (diamond) carbon bonds. You also need simultaneously to increase the...

You might have seen an Iridium flare. The Iridium satellites provide predictable, extremely bright transient flashes. You can learn more about them at http://en.wikipedia.org/wiki/Satellite_flare and http://www.heavens-above.com/ The latter site will display time and location of...