Will definitely need to review the article- one concerning item is the left hand most image is most likely beam deposition from the SEM- when you sit for a while up close then zoom out, the sample can be contaminated with carbon deposition from the ebeam and gas inside. This was often easily seen on a Jeol system I used to use all the time- it even has a point that may be considered a sync position, but the Joel’s beam raster sync was always upper left corner- here it shows lower right corner- but may be a different machine with different scan type/sync position for the beam raster.
It’s a shame the left image above is used, it shows maybe the operator isn’t very up on this technology and artifacts. I only add this as a cautionary point, not to degrade from the discussion- as more eyes on these materials is a very good thing. And I’m sure some of his findings our sound.
Thanks for posting! Will try and view the original article without Js- but I appreciate the added text here! Cheers!
That’s ok- sorry for that! I’m happy to explain anytime. I always tell my fellow coworkers or students in the past: don’t assume I’m right, dig and let me know if I’m wrong. ;)
In this case the environment in the vacuum chamber of the SEM isn’t a perfect vacuum- especially if you have outgassing samples or a lot of organics- when this is the case, you can bake various gaseous things onto the sample with the heat of the e-beam. The ebeam is like an old TV set- the beam rasters back and forth. When we sit zoomed in on a sample, the local ebeam energy is pretty high, and we can bake on material from the gas around it- then when we zoom out, the material we deposited will have the same shape as our view-screen/tv screen because thats where the ebeam rasters across the surface while looking zoomed in. So in this case the fact the rectangle is almost a perfect match for the screen’s aspect ratio, makes me wonder if I’m just looking at “beam damage” or “beam deposition” would be similar phrases. Although damage usually means actual damage and not deposition. Basically it’s not the sample, but what was baked onto the sample. I add it here because this type of mistake ends up making the researcher look silly- even if they have important contributions to make- which is a shame. I’ll try and review the article when I can- working for the man at the moment, but was happy to see a high tech microscope used here. Usually for organics it’s not too common to use SEM- but they have more capable organic compatible microscopes these days. :). So- kudos to the researchers- I just wish they had caught that first image on the left and not included it.
Will definitely need to review the article- one concerning item is the left hand most image is most likely beam deposition from the SEM- when you sit for a while up close then zoom out, the sample can be contaminated with carbon deposition from the ebeam and gas inside. This was often easily seen on a Jeol system I used to use all the time- it even has a point that may be considered a sync position, but the Joel’s beam raster sync was always upper left corner- here it shows lower right corner- but may be a different machine with different scan type/sync position for the beam raster.
It’s a shame the left image above is used, it shows maybe the operator isn’t very up on this technology and artifacts. I only add this as a cautionary point, not to degrade from the discussion- as more eyes on these materials is a very good thing. And I’m sure some of his findings our sound.
Thanks for posting! Will try and view the original article without Js- but I appreciate the added text here! Cheers!
Thanks for your analysis. I would not have knowledge of possible artifacts, but this will help people dig into the details
That’s ok- sorry for that! I’m happy to explain anytime. I always tell my fellow coworkers or students in the past: don’t assume I’m right, dig and let me know if I’m wrong. ;)
In this case the environment in the vacuum chamber of the SEM isn’t a perfect vacuum- especially if you have outgassing samples or a lot of organics- when this is the case, you can bake various gaseous things onto the sample with the heat of the e-beam. The ebeam is like an old TV set- the beam rasters back and forth. When we sit zoomed in on a sample, the local ebeam energy is pretty high, and we can bake on material from the gas around it- then when we zoom out, the material we deposited will have the same shape as our view-screen/tv screen because thats where the ebeam rasters across the surface while looking zoomed in. So in this case the fact the rectangle is almost a perfect match for the screen’s aspect ratio, makes me wonder if I’m just looking at “beam damage” or “beam deposition” would be similar phrases. Although damage usually means actual damage and not deposition. Basically it’s not the sample, but what was baked onto the sample. I add it here because this type of mistake ends up making the researcher look silly- even if they have important contributions to make- which is a shame. I’ll try and review the article when I can- working for the man at the moment, but was happy to see a high tech microscope used here. Usually for organics it’s not too common to use SEM- but they have more capable organic compatible microscopes these days. :). So- kudos to the researchers- I just wish they had caught that first image on the left and not included it.