Talk:Transmission electron microscopy

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12:27, 4 December 2005 Average Earthman  >  Gives the wrong impression - you don't need a monochromator to do EELS.

So please give an example! Or do you mean, I should have followed Electron spectrometer and say spectrometer? But how come, most EELS images are color images, one color for each element. No spectrum.--Arnero 19:47, 6 December 2005 (UTC)

Well, a spectrometer is in a sense also a monochromator. But I believe the point Average Earthman was trying to make was that you do not need a monochromatic incident electron beam in order to perform EELS. Of course, the more monochromatic the incident beam is, the higher the energy resolution that can be obtained in the energy loss spectrum. You do, of course, need some sort of post-specimen spectrometer.O. Prytz 15:15, 18 December 2005 (UTC)

Thanks, I moved on to Energy Filtered transmission Electron Microscopy. --Arnero 18:13, 18 December 2005 (UTC)

Someone has included a sentence about "RTPEM" technique at the end of "applications of.." does anyone know what RTPEM is? O. Prytz 14:22, 26 December 2005 (UTC)

Never heard of it (yet). I don't think we should just have swathes of acronyms with no explanation or suggestions for further reading, so until we get some citation to a journal paper and expansion of this I don't think it belongs here and have deleted it. I tried a quick google and searched on a couple of journals, but can't find anything from just the acronym. Average Earthman 15:33, 26 December 2005 (UTC)
I agree. I also tried a quick search and nothing turned up. Let's see if that editor comes back with an expanation.O. Prytz 15:56, 26 December 2005 (UTC)
It has exactly one search result at Google Scholar. This is certainly a non-notable, if not self-serving, link. eaolson 17:04, 26 December 2005 (UTC)
If the search results on Google scholar were the ones I've seen, they're a particular sequence of amino acids and something to do with lepton-hadron reactions. Not promising leads if you are looking for a TEM application. Of course, he may have meant "RPTEM", but that's no better. Average Earthman 22:16, 26 December 2005 (UTC)

Contents

[edit] Merging?

It has been suggested that selected area diffraction be merged into this article. I think the content of that article is too detailed to be included into this one, so I'm removing the tag. However, we might consider expanding this article with a brief section on diffraction in TEM, with links to the electron diffraction and selected area diffraction articles. O. Prytz 23:40, 11 March 2006 (UTC)

I still feel that the selected area diffraction article is too detailed for merging with this one, but it was previously suggested that selected area diffraction be merged with electron microscope, which I think is inappropriate. Let's discuss this further at talk:selected area diffraction. O. Prytz 23:15, 7 October 2006 (UTC)

[edit] X-ray focussing limitations??

The statement that, "shorter wavelengths, such as X-rays, exhibit a lack of interaction: both in focussing (nothing interacts strongly enough to act as a lens)" may require revision. This is not my area of specialty, however consider the use of x-ray sources in solution-phase diffraction-based structural determinations (~0.01 angstrom spatial resolution):

        SCIENCE VOL 309 19 AUGUST 2005, pp. 1223-7
        Ultrafast X-ray Diffraction of Transient Molecular Structures in Solution
        H. Ihee, M. Lorenc, T.K. Kim, Q.Y. Kong, M. Cammarata, J.H. Lee, S. Bratos, M. Wulff

We report direct structural evidence of the bridged radical (CH2ICH2I) in a polar solution, obtained using time-resolved liquid-phase x-ray diffraction. This transient intermediate has long been hypothesized to explain stereochemical control in many association and/or dissociation reactions involving haloalkanes. Ultrashort optical pulses were used to dissociate an iodine atom from the haloethane molecule (C2H4I2) dissolved in methanol, and the diffraction of picosecond x-ray pulses from a synchrotron supports the following structural dynamics, with ~0.01 angstrom spatial resolution and ~100 picosecond time resolution... HarriemkaliHarriemkali

I am not an expert, but i believe that exploits periodicity to obtain the improved spatial resolution. Similarly to Bragg diffraction giving plane spaces smaller than the x-ray wavelength, as for interaction synchrotron sources are extremely bright. User A1 13:49, 6 June 2007 (UTC)

[edit] Picture Label?

I think that image of Staph aureus is an SEM. Yes no?

  • The original source of the image states it is a TEM sample produced by freeze drying. 128.243.220.41 14:00, 13 December 2006 (UTC)
  • Someone else removed the picture as well. I reverted the change. The micrograph appears to have been published in Guidry et al. Journal of Dairy Science. 74. 3360 (1991). It is also on the web at [1], where it is described as a TEM image. eaolson 04:09, 18 January 2007 (UTC)
    • I emailed the author of that image and he confirmed that it is a TEM image, prepared by shadowcasting a freeze dried sample. Someone has replaced with another TEM image, but I won't revert it since the new one is also a good example TEM micrograph. eaolson 02:36, 19 January 2007 (UTC)

[edit] Transmission electron microscopy involves the transmission of electrons THROUGH a specimen to produce an image.

I changed the incorrect introduction to this article. It should not say that a beam of electrons is focused ONTO a specimen causing an enlarged version to appear on a screen or on film. The imaging system, to which the electrons are directed AFTER they are transmitted THROUGH the specimen, is what causes an image. --207.62.177.227 18:10, 9 March 2007 (UTC)

[edit] Al-Cu Image

Al-Cu alloy
Al-Cu alloy

Hello, i uploaded a BF image of an Al-Cu alloy. Would this be useful in this article? User A1 13:53, 6 June 2007 (UTC)

[edit] Magnetic fields

The article stated that magnetic fields are measured in amperes per metre, which is wrong. I'll change it to teslas.

Another thing: this article (as well as the general EM one) has poor punctuation and grammar at times.

Sorry if any of this does not go here.

VonCarrigan 05:28, 27 September 2007 (UTC)

EDITED: Actually, the units might be right (if referring to the H field), but still be wrong if referring to B. If someone else knows better and I was wrong, they can revert it. VonCarrigan 05:49, 27 September 2007 (UTC)

[edit] Images

This article, like the SEM article, is in sore need of some good, modern, TEM images of both biological and materials topics. --Blechnic (talk) 06:55, 8 April 2008 (UTC)