Virtual (BF/DF) imaging reveals the position and concentration of precipitates in a Ni-W alloy

Gatan instrument used

The K3^® IS camera delivers simultaneous low-dose imaging via real-time electron counting, fast continuous data capture, and a large field of view (FOV). In a 4D STEM experiment, the STEMx^® system precisely synchronizes the speed of the scanning probe to the camera frame rate to enable high-speed data acquisition and eliminates the potential for data loss.

Background

Ni-W based alloys have potential applications in the nuclear industry and national defense due to their superior corrosion resistance, mechanical properties, and higher density. The performance of these alloys can be tailored by the addition of a variety of precipitates at different compositions. Traditionally, dark-field (DF) TEM images are acquired to locate the precipitates in a thin film TEM specimen. If one is interested in covering a broad range in reciprocal space, then the objective aperture would be moved manually, and several images would have to be captured. This is a laborious and time-consuming task on the microscope.