A new compound in the Nb–V–Sb–O system and its physicochemical characteristic

•The new ceramic compound of the formula Nb6VSb3O25 in the Nb–Sb–V–O system is formed.•Nb6VSb3O25 is semiconductor, crystallizes in the orthorhombic system.•Nb6VSb3O25 melts incongruently at 930 ± 5 °C.•The solid product of melting of Nb6VSb3O25 is Nb9VO25.

A new compound of the formula Nb6VSb3O25 in the Nb–V–Sb–O system was characterized by the XRD, SEM/EDX, DTA–TGA, IR and UV–Vis–DR methods. The new compound was obtained in air atmosphere as a result of solid-state reaction between the oxides V2O5, Nb2O5 and Sb2O4 or Sb2O3, mixed at the molar ratio 1:6:3. Nb6VSb3O25 is a semiconductor with band gap energy 3.2 eV, crystallizes in the orthorhombic system, and melts incongruently at 930 ± 5 °C with deposition of solid Nb9VO25. The unit cell parameters of Nb6VSb3O25 were calculated and its IR spectrum was presented.