Talk:Diamond anvil cell

Merged version
A Diamond Anvil Cell (DAC) is used for high pressure experiements. The sample is placed between two diamonds. A gasket keeps the sample in place, and a liquid often ensures even pressure.

This technique is used in synchrotron research.


 * This last claim I find totally mysterious. --Andrew 23:11, Apr 16, 2005 (UTC)


 * A citation is sought for the production of metallic hydrogen using the diamond anvil, for which purpose the following, taken from the article Metallic Hydrogen, would seem to suffice:[3] S. T. Weir, A. C. Mitchell, and W. J. Nellis, Metallization of Fluid Molecular Hydrogen at 140 GPa (1.4 Mbar) Physical Review Letters 76, 1860 - 1863 (1996). Unfortunately, while I was able to simply paste the citation at the end of the article, I was unable to figure out how to properly insert the reference. Help appreciated. FutharkRed 07:34, 14 February 2007 (UTC)


 * FutharkRed, the citation you give describes an experiment using shock compression. This is an entirely different technique than using a diamond anvil cell.  In a shock experiment the pressure is only maintained for a few tiny fractions of a second and the temperature is very high so that the hydrogen was fluid.  Metallic hydrogen has not yet been produced in a diamond anvil cell.  Thus, I've removed the incorrect statement about metallic hydrogen being produced in a diamond anvil cell from the article. —Preceding unsigned comment added by JazHambo (talk • contribs)


 * Thanks JazHambo, good work. - Eldereft (cont.) 08:06, 18 October 2008 (UTC)

Diagram
The diagram demonstrating the technique is technically incorrect. It suggests that the laser beam (and X-rays, although this at least is more plausable) comes in from the side at an angle parellel to the principle facet of the diamond (ie: normal to the applied force). In order to do this the laser would need to pass through the gasket which is generally opaque. The more usual method (and indeed the reason why a DAC is so useful) is to pass the laser beam along the axis of applied force and through the diamond. The diamond is transparent (which is one of the reasons a high purity, well cut diamond is required) and has very little effect on the laser beam (or at least one which can be corrected or accounted for in results). I'm a little unsure what the copyright on the image allows me to do with it though and it would be a shame to have to totally replace the entire image when a little editing is all that is required to fix the problem (ie: slightly expand the frame and redraw the arrows coming in from the right direction). Could someone clarify if it's ok for me to fix this and resubmit the corrected image or does modification violate the copyright? --Edith The Hutt 18:59, 5 October 2006 (UTC) The image is in the public domain, and therefore you may edit it in anyway you like.


 * I found hard to fix the discussed image by editing and simply replaced it with a better one. NIMSoffice (talk) 10:45, 21 January 2009 (UTC)


 * I added a new picture that I drew for a lab report. I tried to make it as accurate as possible. --Tobias1984 (talk) 19:16, 12 May 2012 (UTC)

Gasket material
A quick quibble - beryllium gaskets are metallic but basically x-ray transparent. We could change the statement in Components to just say that low Z materials can be used for illumination through the gasket, or possibly briefly list desirable characteristics with examples: x-ray transparency (Be, B); high stiffness (Re, diamond-coated); high yield strength (spring steel). Actually, those are the only gasket materials that occur to me off hand - am I missing any? Trade-offs would include toxicity/ease of handling, plastic deformation, sample containment/centering, thermal/chemical stability, &c. Thoughts? - Eldereft (cont.) 18:16, 22 January 2009 (UTC)


 * New edit fixed this - good job. - Eldereft (cont.) 22:02, 23 January 2009 (UTC)

What limits the maximum pressure
Is the maximum pressure achievable the ultimate compressive strength of diamond or it is limited by the compressive or tensile strength of the gasket material ? It would be great if the Principle section could clarify. Rod57 (talk) 18:43, 27 March 2011 (UTC)