Preparation and band gap tailing of ternary Zn1−xCdxWO4 nanocrystals by mechanical alloying

Zn1−xCdxWO4(x = 0-1) nanocrystals were fabricated by mechanical alloying in the air. The high impact energy of SPEX machine transformed the single oxides of ZnO, CdO and WO3 with a designed molar ratio into the ternary Zn1−xCdxWO4 compounds through mechanochemical reaction. The as-milled products exhibit single phase without any impurity, have an average size less than 10 nm, perform indirect band gap semiconductor feature and tunable band gap energies upon the composition x. The resulting nanocrystals show a linear lattice parameter-composition and quadratic band gap-composition relationships. The valence band edge of the ternary oxides shifts to lower energy side with x value, which enlarges the band gap of the compound.