The Dresden in-situ (S)TEM special with a continuous-flow liquid-helium cryostat

TL;DR

This paper presents a novel in-situ (S)TEM setup with a continuous-flow liquid-helium cryostat, enabling precise temperature control from 6.5 K to 400 K and a large experimental space, improving low-temperature material studies.

Contribution

The development of a Dresden in-situ (S)TEM with an expanded space and precise temperature control using a continuous-flow cryostat is a significant technical advancement.

Findings

Achieved a 5 nm information limit in resolution.

Demonstrated stable temperature control over days.

Identified external instabilities as current resolution limit.

Abstract

Fundamental solid state physics phenomena typically occur at very low temperatures, requiring liquid helium cooling in experimental studies. Transmission electron microscopy is a well-established characterization method, which allows probing crucial materials properties down to nanometer and even atomic resolution. Due to the limited space in the object plane, however, suitable liquid-helium cooling is very challenging. To overcome this limitation, resolving power was sacrificed in our Dresden in-situ (S)TEM special, resulting in more than 60 mm usable experimental space in all directions with the specimen in the center. With the installation of a continuous-flow liquid-helium cryostat, any temperature between 6.5 K and 400 K can be set precisely and kept for days. The information limit of the Dresden in-situ (S)TEM special is about 5 nm. It is shown that the resolution of the Dresden in-situ (S)TEM special is currently not limited by aberrations, but by external instabilities, that are currently addressed.