scholarly journals A method for personal expertise-independent evaluation of image resolution in scanning electron microscopy

Scanning ◽  
2006 ◽  
Vol 24 (4) ◽  
pp. 191-203 ◽  
Author(s):  
Tohru Ishitani ◽  
Mitsugu Sato
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Image Resolution ◽  
Independent Evaluation ◽  
Personal Expertise ◽  
Scanning Electron

Low-voltage, high-resolution scanning electron microscopy of polymers

1987 ◽  
Vol 45 ◽  
pp. 466-467 ◽  
Author(s):  
S. J. Krause ◽  
W.W. Adams ◽  
S. Kumar ◽  
T. Reilly ◽  
T. Suziki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Resolution Limit ◽  
Crossover Point ◽  
New Generation ◽  
Beam Damage ◽  
Scanning Electron

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. Imaging polymer samples with low accelerating voltages (0.1 to 2.0 keV), at or near the “crossover point”, can reduce beam damage, eliminate charging, and improve contrast of surface detail. However, at low voltage, beam brightness is reduced and image resolution is degraded due to chromatic aberration. A new generation of instruments has improved brightness at low voltages, but a typical SEM with a tungsten hairpin filament will have a resolution limit of about 100nm at 1keV. Recently, a new field emission gun (FEG) SEM, the Hitachi S900, was introduced with a reported resolution of 0.8nm at 30keV and 5nm at 1keV. In this research we are reporting the results of imaging coated and uncoated polymer samples at accelerating voltages between 1keV and 30keV in a tungsten hairpin SEM and in the Hitachi S900 FEG SEM.

scholarly journals Dental macro- and microwear in Carinodens belgicus, a small mosasaur from the type Maastrichtian

2013 ◽  
Vol 92 (4) ◽  
pp. 267-274 ◽  
Author(s):  
F.M. Holwerda ◽  
B.L. Beatty ◽  
A.S. Schulp
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Feeding Behaviour ◽  
Benthic Organisms ◽  
Minimum Width ◽  
Independent Evaluation ◽  
Dietary Niche ◽  
Food Particles ◽  
Oral Processing ◽  
Scanning Electron

AbstractTeeth of the small durophagous mosasaur Carinodens belgicus are known from Maastrichtian Atlantic-Tethyan deposits worldwide. The peculiar dentition of Carinodens inspired debate and speculation on its dietary niche ever since its first description. In this contribution, we describe the macro- and microwear pattern in five well-preserved isolated teeth, allowing further and independent evaluation of aspects of feeding behaviour and diet. Macroscopically, wear is concentrated on the apex and mesiodistal sides. Microwear was mapped using Scanning Electron Microscopy at several magnifications and can be characterised as scratches and pits. Coarse scratches were found to be the most common and pits were found to be the least common feature. Scratch orientation is primarily along the mesiodistal plane or in the labiolingual plane with an angle of ~130°. These microwear features can be explained either by oral processing or passive abrasion by sediments or food. As scratch width only indicates the minimum width of the abrading particle, the material causing the wear here could have ranged from silica-based silts to larger abrasives. However, in this case, abrasion by sediments might not explain this wear because of the biocalcarenitic nature of the type Maastrichtian sediments; siliciclastics are virtually absent. Therefore it is more likely that hard food particles, such as benthic organisms with hard exoskeletons, caused the wear on the enamel of Carinodens, or Carinodens ventured out to more sandy areas to forage as well. The mesiodistal and labiolingual direction of the microwear scratches might suggest that Carinodens showed more complexity in the use of its teeth than simple grasping, and that a gripping and pulling motion during feeding similar to that employed by modern varanids may have been the cause.

LOW-VOLTAGE AND ULTRA-LOW-VOLTAGE SCANNING ELECTRON MICROSCOPY OF SEMICONDUCTOR SURFACES AND DEVICES

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4387-4394 ◽  
Author(s):  
JINGYUE LIU
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Image Resolution ◽  
Sem Images ◽  
Conducting Materials ◽  
Low Energies ◽  
Low Energy Electrons ◽  
Voltage Scanning ◽  
Scanning Electron

Low-voltage scanning electron microscopy (LV-SEM) enables us to directly examine non-conducting materials with high spatial resolution. Although use of ultra-low-energy electrons can provide further advantages for characterizing delicate samples, lens aberrations rapidly deteriorates the image resolution. The combined use of a retarding field and the probe-forming lens system can improve the image resolution for electrons with very low energies. In commercially available FEG-SEMs, the retarding field can simply be constructed by applying a negative potential to the specimen. Interesting contrast variations have been observed in ultra-low-voltage SEM images. In this short communication, we discuss the application of LV-SEM to examining semiconductor devices and also the recent development of the ultra-low-voltage SEM technique.

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