High-Pressure Synthesis of Superconducting Sn₃S₄ Using a Diamond Anvil Cell with a Boron-Doped Diamond Heater

High-pressure techniques open exploration of functional materials in broad research fields. An established diamond anvil cell with a boron-doped diamond heater and transport measurement terminals has performed the high-pressure synthesis of a cubic Sn₃S₄ superconductor. X-ray diffraction and Raman spectroscopy reveal that the Sn₃S₄ phase is stable in the pressure range of P > 5 GPa in a decompression process. Transport measurement terminals in the diamond anvil cell detect a metallic nature and superconductivity in the synthesized Sn₃S₄ with a maximum onset transition temperature (T_c^onset) of 13.3 K at 5.6 GPa. The observed pressure-T_c relationship is consistent with that from the first-principles calculation. The observation of superconductivity in Sn₃S₄ opens further materials exploration under high-temperature and -pressure conditions.