Pressure‐Induced Superconductivity and Structure Phase Transition in SnAs‐Based Zintl Compound SrSn₂As₂

Layered SnAs‐based Zintl compounds exhibit a distinctive electronic structure, igniting extensive research efforts in areas of superconductivity, topological insulators, and quantum magnetism. In this paper, the crystal structures and electronic properties of the Zintl compound SrSn 2 As 2 upon compression are systematically investigated. Pressure‐induced superconductivity is observed in SrSn 2 As 2 with a nonmonotonic evolution of superconducting transition temperature T c . Theoretical calculations together with high‐pressure synchrotron X‐ray diffraction and Raman spectroscopy have identified that SrSn 2 As 2 undergoes a structural transformation from a rhombohedral R m phase to the monoclinic C 2 /m phase. Beyond 28.3 GPa, T c is suppressed due to a reduction of the density of state (DOS) at the Fermi level. The discovery of pressure‐induced superconductivity, accompanied by structural transitions in SrSn 2 As 2 , greatly expands the physical properties of layered SnAs‐based compounds and provides new ground states upon compression.