Ta₂NiS₅ (Tantalum Nickel Sulfide)

Ta₂NiS₅ is a quasi-one-dimensional layered transition-metal chalcogenide and a narrow-gap semiconductor (band gap ≈ 0.4 eV), regarded as an excitonic insulator candidate like its selenide sister compound Ta₂NiSe₅. Its low-temperature ground state is thought to be linked to spontaneous condensation of electron–hole excitons, and together with its pronounced quasi-1D anisotropy it serves as a representative system for studying excitonic-insulator physics, band–exciton coupling, and ultrafast optoelectronics. 

Sample specifications: Individual crystals measure approximately 6~8 mm, with a purity of up to 99.9999% (6N), and multiple high-quality single-crystal pieces included in each package.