  Nanoscale superlattices represent a compelling platform for designed
materials as the specific identity and spatial arrangement of constituent
layers can lead to tunable properties. A number of kinetically-stabilized
layered chalcogenide nanocomposites have taken inspiration from misfit
compounds, a thermodynamically stable class of materials formed of van der
Waals-bonded (vdW) layers. This class of vdW heterostructure superlattices have
been reported in telluride and selenide chemistries, but have not yet been
extended to sulfides. Here we present $SnS-TaS_2$ nanoscale superlattices with
tunable layer architecture. Thin films are prepared from layered amorphous
precursors and deposited to mimic the targeted superlattice; subsequent low
temperature annealing activates self-assembly into designed nanocomposites.
Structure and composition for materials are investigated that span stacking
sequences between $[(SnS)_{1+\delta}]_3(TaS_2)_1$ and $(SnS)_7(TaS_2)_1$ using
x-ray diffraction, x-ray fluorescence, and transmission electron microscopy. A
graded deposition approach is implemented to stabilize heterostructures of
multiple stacking sequences with a single preparation. Precise control over the
architecture of such nanoscale superlattices is a critical path towards
controlling the properties of quantum materials and constituent devices.
