Single step combustion synthesis of nanocrystalline scheelite Ba0.5Sr0.5MoO4 for optical and LTCC applications: Its structural, optical and dielectric properties

The synthesis of nanocrystalline Ba0.5Sr0.5MoO4 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 is 21 nm. The ultraviolet-visible absorption spectrum of the sample shows maximum absorption in the UV region and the optical band gap determined is 4.71 eV. The photoluminescence spectrum of Ba0.5Sr0.5MoO4 shows green emission, associated with the perfect order and crystallinity of the sample. The sample is sintered at a relatively low temperature of 815 °C. Scanning electron microscopy showed that the sample achieved 95 % of its theoretical density. The dielectric constant and loss factor of the sample measured at 5 MHz is found to be 10.58 and 1.66.×10−3 at room temperature. The effect of change in composition of A2+ site of scheelite AMO4 compounds comparative are also presented. The experimental results show that nano Ba0.5Sr0.5MoO4 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.