Optical and dielectric investigations of nano crystalline scheelite A0.5B0.5MoO4 (A=B=Ba, Sr and Ca)

The synthesis of nanocrystalline A0.5B0.5MoO4 by an auto-igniting combustion technique is reported. The structural characterization done by X-ray diffraction, Fourier transform Raman spectroscopy and infrared spectroscopy reveals that the as-prepared powder itself is phase pure with tetragonal structure. The particle size determined from Transmission electron microscopy are in the range 23–25 nm. The optical band gap determined show that the compounds are wide bandgap semiconductors. The photoluminescence spectrum of A0.5B0.5MoO4 shows green emission, associated with the perfect order and crystallinity of the sample. All the samples are sintered at a temperature less than 875°C. The dielectric constant and loss factor of the samples are measured at radiofrequency range and its variation with temperature is also studied. The effect of change in composition of A2+ site of scheelite AMO4 compounds comparative are also presented. The experimental results show that nano A0.5B0.5MoO4 is an excellent luminescent material and also a promising ‘Low temperature Co-fired Ceramic. Also it is inferred that we can fine tune both optical and dielectric properties to desired values according to our requirements by adjusting the cationic stoichiometric ratio in [AO8] octahedron.