β-SnWO4 as yellow lead-free pigment by ball milling method: Rietveld refinement, morphology, optical and colorimetric properties

The article presents a new route of synthesis of tin tungstate (β-SnWO4) by high-energy ball milling (HEBM), starting from the precursors metallic tin (Sn) and tungsten trioxide (WO3). After 4 h of grinding, the pure phase was obtained for the beta (β-SnWO4) of cubic structure and space group P213, with a high crystallinity was confirmed by X-ray diffraction (XRD), Rietveld refinement, Raman vibrational spectroscopy. All the characteristic elements of tin tungstate (Sn, W and O) were identified in the analysis by energy dispersive X-ray spectroscopy (EDX). The optical band gap values for the synthesised materials at 4 and 5 h were 2.82 and 2.50 eV, respectively. Finally, the colorimetric properties obtained of sample SW-5h are promising in applications involving pigments free of lead-based compounds, which exhibits colorimetric coordinates L*, a* and b* of 26.52, 0.62 e 17.8, respectively.