Rb8Nb10Ge6O41: A new niobium-germanate crystal featuring unique one-dimensional [Nb7O30] chains and wide mid-IR transparency

A novel niobium germanate Rb 8 Nb 10 Ge 6 O 41 was prepared through spontaneous crystallization, and it exhibits exceptional thermal stability and a wide transparency window of 0.306–6.25 μm with a large band gap of 3.78 eV.