  Transition metal-intercalated transition metal dichalcogenides (TMDs) are
promising platforms for next-generation spintronic devices based on their wide
range of electronic and magnetic phases, which can be tuned by varying the host
lattice or the identity of the intercalant, along with its stoichiometry and
spatial order. Some of these compounds host a chiral magnetic phase in which
the helical winding of magnetic moments propagates along a high-symmetry
crystalline axis. Previous studies have demonstrated that variation in
intercalant concentrations can have a dramatic impact on the formation of
chiral domains and ensemble magnetic properties. However, a systematic and
comprehensive study of how atomic-scale order and disorder impacts collective
magnetic behavior are so far lacking. Here, we leverage a combination of
imaging modes in the (scanning) transmission electron microscope (S/TEM) to
directly probe (dis)order across multiple length scales and show how subtle
changes in the atomic lattice can be leveraged to tune the mesoscale spin
textures and bulk magnetic response, with direct implications for the
fundamental understanding and technological implementation of such compounds.
