Characterization of Thin Films of Mixed Complexes of Rare Earth, Mo and W ions

The structure of new compound of the type [Pr (SH) (OH) 2H2O] has already been established in our earlier publication (JCGCM 2002). When aqueous solution of ammonium molybdate [NH4) 2 MoO4 2H2O] was mixed with Na2S 7H2O, yielded yellow solution due to reducing nature of sodium sulfide. Yellow solution, (NH4) 2 [MoO2 (H2O) 2] was mixed with green solution of the compound, [Pr (SH) (OH) 2H2O], a brownish red color solution [MoO2 (H2O) 2 Pr (SH) (OH) 2 H2O] 2- [NH4] 2+ was obtained which showed transition at 500 nm, intervalence Pr3+ Mo4+ band at 425 nm and a steep broad band from 850 to 950 nm due to H- bonding. When aqueous solution (NH4) 2 [ WO4 2H2O] was mixed with the compound [Pr (SH) (OH) 2 H2O] a green color solution [ WO2 (H2O) 2 Pr (SH) (OH) 2 H2O]2- was obtained which showed intervalence Pr3+ W 3+ band at 500 nm. On addition of an inert solvent CCl4, the steep broad band at 850-950 nm due to H- bonding disappeared, ascertaining the polymeric nature due to H- bonding of the compound. The structure of thin film of solutions was established by XRD pattern, IR spectra, SEM and TEM showed nearly spherical grains having average size 50-100 nm.