Reducing the missing wedge: High-resolution dual axis tomography of inorganic materials

Abstract

Electron tomography is a powerful technique that can probe the three-dimensional (3-D) structure of materials. Recently, this technique has been successfully applied to inorganic materials using Z-contrast imaging in a scanning transmission electron microscope to image nanomaterials in 3-D with a resolution of 1 nm in all three spatial dimensions. However, an artifact intrinsic to this technique limits the amount of information obtainable from any object, namely the missing wedge. One way to circumvent this problem is to acquire data from two perpendicular tilt axes, a technique called "dual axis tomography." This paper presents the first dual axis data at high resolution for inorganic materials, and by studying a CdTe tetrapod sample, demonstrates the increase in information obtained using this technique.