Authors : S. N. Nadaf, T. J. Shinde, P. N. Bhosale, V. A. Kalantre and S. R. Mane
Page Nos : 126-130
Description :
In present investigation, thin films of molybdenum heteropolyoxometalate viz. undoped phosphomolybdic acid [H3 (PMo12 O40)] and Cs+ doped phosphomolybdic acid [Cs3 (PMo12 O40)] were deposited at optimum deposition conditions by hydrothermally growth process using aqueous solutions. Structural and electrical properties of undoped and Cs+ doped molybdenum heteropolyoxometalate thin films have been investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used to study the structural properties of the materials. Morphological study shows that, with Cs+ doping grain becomes spherical than undoped one. X-ray diffraction study revealed that, the material is polycrystalline in nature having simple cubic spinel structure. After doping Cs+ intensity of prominent peak (311) increases and other peaks are suppressed indicating intercalations of Cs+ in the octahedral lattice of phosphomolybdate anion without change in crystal structure. The optical absorption study revealed that, there is decrease in band gap (Eg) of material after doping Cs+. DC electrical conductivity shows that, after Cs doping conducting and semiconducting behavior is observed at lower temperature. TEP study shows that, there is improvement in the p-type conducting behavior after Cs doping. The TGA-DTA study revealed that, after doping Cs+, stability of Cs3 (PMo12 O40) material increases and the material is thermally stable up to 687.610C.
Keywords: Hydrothermal, heteropolyoxometalate, thin films, electrical conductivity.
