Zn1-xCoxWO4 (0 ≤ x ≤ 1) full range solid solution: Structure, optical properties, and magnetism

A novel full-range solid-solution Zn1-xCoxWO4 (0 <= x <= 1) was successfully developed via a facile one-pot hydrothermal route. The phase structure and microstructure were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra and scanning electron microscopy (SEM). The Zn1-xCoxWO4 solid solution possesses similar wolframite crystal structure with the same space group P2/c. Diffuse reflection spectroscopy (DRS) measurements on Zn1-xCo WO4 (0 <= x <= 1) demonstrated that the optical band gap can be continuously tuned from 3.56 eV to 2.61 eV for direct transition and 1.87 eV for indirect transition, respectively, with increasing x from 0 to 1. Magnetic susceptibility measurements reveal that CoWO4 has an antiferromagnetic transition at T-N = 42K, whereas Zn0.5Co0.5WO4 exhibits paramagnetic behavior. Moreover, CoWO4 and Zn0.5Co0.5WO4 obey the Curie-Weiss law from 200 k down to 50K, and their effective magnetic moments were determined. (C) 2015 Elsevier Ltd. All rights reserved.