Vibrational, Electronic and Structural Study of Sprayed ZnO Thin Film Based on the IR-Raman Spectra and DFT Calculations

Applying the Density Function Theory (DFT) combined with LCAO basis set and employing the B3LYP hybrid functional, the optimized geometrical parameters, electronic properties, as well as the Infrared and Raman spectra for wurtzite-ZnO structure were investigated. Prior to computing, ZnO thin film prepared by the spray pyrolysis method is characterized by X-ray diffraction using Rietveld refinement. This analysis shows that ZnO has hexagonal wurtzite structure (P63mc) with lattice parameters, a = 3.2467 and c = 5.2151 Åin good agreement with our predicted optimized geometry. Atomic force microscopy (AFM), Raman spectroscopy and UV-Vis-NIR spectrophotometry techniques are used to explore morphological, optical and vibrational properties of the sprayed ZnO thin film. The computed band gap is in excellent agreement with that deduced from UV-Vis transmission . The simulated infrared and Raman spectra were also calculated, and a good agreement with the measured spectra is obtained. Finally, a detailed interpretation of the infrared and Raman spectra is reported.

DFT study on the structure and spectra of GasP5 cluster

In this paper, possible structures of GasP5 cluster were optimized by using density functional method with generalized gradient correction （B3LYP）. The electronic structure of the isomers with lower energy was studied. The most stable structure obtained for GasP5 is a distorted pentaprism. The Ga-P bond formed in the cluster is strongly ionic. Based on NBO analysis, an average value of 0.59 electron transfers from Gallium to Phosphorus. The bond length 2.33-2.43 is around the value in bulk GaP. The HOMO-LUMO gap is about 2.2 eV. The dipole moment and polarizability are calculated, and the IR and Raman spectra are also presented.

Tunable LCST-type phase behavior of [FeCl4]--based ionic liquids in water

In this work, 16 kinds of [FeCl4]--based magnetic ionic liquids （ILs） with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then the lower critical solution temperature （LCST）-type phase behavior of these magnetic ILs in water is investigated as a function of concentration. It is shown that cat- ion structure, alkyl chain length and molar ratio of FeCl3/chloride IL have a significant influence on the LCST of the mixtures. The phase separation temperature can be tuned efficiently by these factors. Meanwhile, the LCST-type phase separation pro- cess is also investigated by dynamic light scattering. The results support the mechanism that the hydrogen bonds of the [Fefl4]- anion with water have been gradually disrupted to form ILs aggregates with increasing temperature. In addition, the stability of the ILs in water is also examined in some details. These LCST-type phase separation systems may have potential applications in extraction and separation techniques at room temperature.