Data and code from: Dark field X-ray microscopy below liquid-helium temperature: The case of NaMnO2

Dark field X-ray microscopy (DFXM) is an experimental technique employed
to investigate material properties by probing their ‘mesoscale,’ or
microscale structures, in a bulk-sensitive manner using hard X-rays at
synchrotron radiation sources. However, challenges remain when it comes to
applications of this technique to examine low-temperature phenomena in
quantum materials, which exhibit complex phase transitions at cryogenic
temperatures. One such material is NaMnO2, which hosts an
antiferromagnetic transition at 45 K that is suspected to coincide with
local structural transitions from its majority monoclinic phase to
nanoscale triclinic domains. Direct observation of local heterogeneities
and this effect at low temperatures in NaMnO2 is an important step in
understanding this material, and serves as an ideal candidate study for
expanding the DFXM experimental design space. This paper details a
foundational high-resolution DFXM study, down to liquid-helium temperature
and below, conducted to explore phase transitions in NaMnO2. The outlined
experiment ushers in the evaluation of other functional materials at low
temperatures using this technique.