Structure, optical properties, and magnetism of Zn1−xNixWO4 (0 ⩽ x ⩽ 1) solid solution

• A novel Zn1−xNixWO4 (0 ⩽ x ⩽ 1) solid solution was synthesized by a two-step method.
• They all present a single-phase in the wolframite structure with space group P2/c.
• The continuous tenability in band gap was achieved in Zn1−xNixWO4 (0 ⩽ x ⩽ 1).
• NiWO4 and Zn0.5Ni0.5WO4 exhibit paramagnetic behavior and obey the Curie–Weiss law.

A novel Zn1−xNixWO4 (0 ⩽ x ⩽ 1) solid solution with full compositions range has been successfully developed by a hydrothermal–annealing method for the first time. The crystal structure was characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra and scanning electron microscopy (SEM). It was found that the entire range of compositions display a single-phase in the wolframite structure with a symmetry P2/c. The diffuse reflection spectroscopy (DRS) measurements on Zn1−xNixWO4 (0 ⩽ x ⩽ 1) indicated that the optical band gap size across the solid solution exhibits red-shifts from 2.8 eV to 1.63 eV for indirect transition and 3.56 eV to 2.77 eV for direct transition with the increase of Ni2+ content. As deduced from the magnetic susceptibility measurements on NiWO4 and Zn0.5Ni0.5WO4, they are paramagnetic and obey the Curie–Weiss law. Moreover, their effective magnetic moments are determined to be 9.96μB and 6.45μB, respectively.

The crystal structure modulation and continuous tenability in band gap were achieved in the Zn1−xNixWO4 (0 ⩽ x ⩽ 1) full range solid solution.Figure optionsDownload as PowerPoint slide