Growth, characterization and dielectric studies of yttrium heptamolybdate system by gel method.

摘要

Synthesis of yttrium heptamolybdate system has been achieved by room temperature solution growth method known as gel encapsulation technique. The system used is Y(NO3)3 - (NH4)6Mo7O24 - NH4NO3 - HNO3 - Na2SiO3. Various experiments were performed in order to find the optimum conditions conducive for the growth of yttrium heptamolybdate. The maximum size of the material synthesized in the form of crystals was 1mm3. X-ray diffraction analysis (XRD) studies reveal the crystalline nature of the grown material whereas the morphology was established by scanning electron microscopy (SEM). Energy dispersive X - ray analysis (EDAX) establishes stoichiometry of the grown crystal as Y2Mo7O24.xH2O. Fourier transform infrared spectroscopy (FTIR) studies signify the presence of heptamolybdate ion and water of crystallization. The dielectric constant measurements were found to be strongly dependent on frequency and temperature. The dielectric constant behavior reveals that the yttrium heptamolybdate could be ferroelectric.