Sandia National Laboratories' new aberration-corrected scanning transmission microscope has a unique combination of X-ray detectors and very high resolution, and is capable of doing analyses in far less time than its predecessor (credit: Randy Montoya/Sandia National Laboratories)

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.

The image on the left was captured in seven minutes at 0.5nm/pixel with Sandia's new AC-STEM; the image on the right was captured in 120 minutes at 2nm/pixel with the old microscope. The analytical power of the AC-STEM is at least 70 times better than the older analytical microscope at Sandia. These high-resolution chemical images are confirming predictions from the 1970s regarding the atomic-scale characteristics of electrical contact materials. (Credit: Sandia National Laboratories)

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.