Small worlds come into focus with new Sandia microscope
June 12, 2012
Sandia’s new aberration-corrected scanning transmission electron microscope (AC-STEM) is 50 to 100 times better than what came before, both in resolution and the time it takes to analyze a sample.
The AC-STEM delivers electron beams accelerated at voltages from 80 kV to 200 kV, allowing researchers to study properties of structures at the nanoscale — crucial for materials scientists working on everything from microelectronics to nuclear weapons.
The remote operation affords another advantage: researchers at Sandia’s California site can run it from 1,000 miles away, which they demonstrated in March.
Older instruments were limited by lens aberrations, particularly spherical aberration that prevents sharp focus because electrons off the optical axis are focused more strongly than ones near the optical axis, principal investigator Kotula said. The AC-STEM’s additional lenses and computational elements eliminate such problems.