Resolution improvement of differential phase-contrast microscopy via tilt-series acquisition for environmental cell application.

A simple method that improves the resolution of phase measurement in differential phase-contrast scanning transmission electron microscopy for closed-type environmental cell applications was developed and tested using a model sample simulating environmental cell observations. Because the top and bottom membranes of an environmental cell are typically far apart, the images from these membranes are shifted widely by tilt-series acquisition, and averaging the images after alignment can effectively eliminate undesired signals from the membranes while improving the signal from the object of interest. It was demonstrated that a phase precision of 2π/100 rad is well achievable using the proposed method for the sample in an environmental cell.