Formation of complete solid solutions, Zn(AlxGa1−x)2O4 spinel nanocrystals via hydrothermal route

Abstract Spinel-structured complete solid solutions: Zn(Al x Ga 1− x ) 2 O 4 , x =0–1.0 were directly formed as nanocrystals from the aqueous precursor solutions of inorganic metal salts under hydrothermal conditions at 240 °C for 5 h in the presence of tetramethylammonium hydroxide. The crystallite size of the spinel varied from 14.5 to 5 nm with increased Al atomic ratio, x in the composition from x =0 to 1.0. The linear decrease in the lattice parameter of the spinel phase by the substitutional incorporation of Al into the lattice nearly followed the Vegard׳s law though a slight positive departure from the law was observed. The incorporation of Al into the lattice, Zn(Al x Ga 1− x ) 2 O 4 resulted in wider optical band gap due to the blue shift of absorption spectra. The broad-band UV–visible blue light emission centered at around 480 nm that was observed under excitation at 270 nm Xe lamp in the ZnGa 2 O 4 spinel showed blue shift by the incorporation of Al into the lattice, Zn(Al x Ga 1− x ) 2 O 4 .