Scanning Electron Microscopy – Field Emission
The field emission scanning electron microscope (JEOL JSM 7100 FT FE-SEM) at Microtrace provides a new level of resolution and intensity over a conventional SEM. The FE-SEM provides numerous benefits, which include working at much higher magnification, achieving higher resolutions (1 nm), and conducting elemental analysis (EDS analysis) on smaller particles or objects. The instrument is equipped with an energy filtered secondary electron detector, a short working distance backscatter electron detector which enables working at low voltages, and a through the lens detectors, which can be used individually or in concert to provide numerous types of image contrast. A gentle beam mode permits analysis of nonconductive and other samples susceptible to charging through the use of a stage deceleration mechanism. The column is designed to provide an extremely wide range of currents (5 pA to 200 nA) and operating voltages (100 V to 30 kV) under extremely stable conditions that permit resolution to be maintained, even at high probe currents. Ultimately, this instrument provides the highest microanalysis resolution of any instrument in our laboratory, with the exception of the transmission electron microscope.
To alleviate charging and increase resolution, beam deceleration (gentle beam) effectively reduces the acceleration voltage to the sample by applying a negative bias to the sample. This effectively increases resolution by maintaining higher kV in the gun & column (reduces aberrations) and accelerates secondary electrons off the sample, especially at very low accelerating voltages improving signal to noise ratio. This mode also serves to reduce charging and contamination and increases the level of pure surface topographic detail (due to reduced beam penetration).
Elemental analysis and elemental mapping can be conducted at nanoscale resolution using a 50 mm² Oxford silicon drift detector. This system contains a drift correction algorithm to ensure that even the smallest areas can be mapped at a high degree of spatial accuracy. Read more about our elemental analysis capabilities here.
Related Standardized Methods: ASTM C1723, E1508, E1588, E2809, F1372