Synthesis, photoluminescence and magnetic properties of barium vanadate nanoflowers

The flower-shaped barium vanadate has been obtained by the composite hydroxide mediated (CHM) method from V2O5 and BaCl2 at 200 °C for 13 h. XRD and XPS spectrum of the as-synthesized sample indicate it is hexagonal Ba3V2O8 with small amount of Ba3VO4.8 coexistence. Scan electron microscope and transmission electron microscope display that the flower-shaped crystals are composed of nanosheets with thickness of ∼20 nm. The UV–visible spectrum shows that the barium vanadate sample has two optical gaps (3.85 eV and 3.12 eV). Photoluminescence spectrum of the barium vanadate flowers exhibits a visible light emission centered at 492 and 525 nm which might be attributed to VO4 tetrahedron with Td symmetry in Ba3V2O8. The ferromagnetic behavior of the barium vanadate nanoflowers has been found with saturation magnetization of about 83.50 × 10−3 emu/g, coercivity of 18.89 Oe and remnant magnetization of 4.63 × 10−3 emu/g, which is mainly due to the presence of a non-orthovanadate phase with spin S = 1/2.