Hybrid semiconductor–superconductor
nanowires constitute
a pervasive platform for studying gate-tunable superconductivity and
the emergence of topological behavior. Their low dimensionality and
crystal structure flexibility facilitate unique heterostructure growth
and efficient material optimization, crucial prerequisites for accurately
constructing complex multicomponent quantum materials. Here, we present
an extensive study of Sn growth on InSb, InAsSb, and InAs nanowires
and demonstrate how the crystal structure of the nanowires drives
the formation of either semimetallic α-Sn or superconducting
β-Sn. For InAs nanowires, we observe phase-pure superconducting
β-Sn shells. However, for InSb and InAsSb nanowires, an initial
epitaxial α-Sn phase evolves into a polycrystalline shell of
coexisting α and β phases, where the β/α volume
ratio increases with Sn shell thickness. Whether these nanowires exhibit
superconductivity or not critically relies on the β-Sn content.
Therefore, this work provides key insights into Sn phases on a variety
of semiconductors with consequences for the yield of superconducting
hybrids suitable for generating topological systems.