No abstract

No abstract

Silver (Ag) nanoparticles are of great interest for many applications. However, their fabrications have been limited by the synthesis methods in which size, shape, and aggregation are still difficult to control. Here, we reported on using direct current (DC) magnetron sputtering for growing Ag nanoparticles on unheated substrates. Effects of sputtering condition on grain size of Ag nanoparticle were discussed. At constant sputtering current and deposition time, the average sizes of Ag nanoparticles were 5.9 ± 1.8, 5.4 ± 1.3, and 3.8 ± 0.7 nm for the target-substrate distances of 10, 15, and 20 cm, respectively. The morphology evolution from nanoparticles to wormlike networks was also reported. High-resolution transmission electron microscopy image represented clear lattice fringes of Ag nanoparticles with a d-spacing of 0.203 nm, corresponding to the (200) plane. The technique could be applied for growth of nanoparticles that were previously difficult to control over size and size uniformity.

No abstract

No abstract

Al2O3nanoparticles were synthesized using laser ablation of an aluminum (Al) target in deionized water. Nd:YAG laser, emitted the light at a wavelength of 1064 nm, was used as a light source. The laser ablation was carried out at different energies of 1, 3, and 5 J. The structure of ablated Al particles suspended in deionized water was investigated using X-ray diffraction (XRD). The XRD patterns revealed that the ablated Al particles transformed intoγ-Al2O3. The morphology of nanoparticles was investigated by field emission scanning electron microscopy (FE-SEM). The FE-SEM images showed that most of the nanoparticles obtained from all the ablated laser energies have spherical shape with a particle size of less than 100 nm. Furthermore, it was observed that the particle size increased with increasing the laser energy. The absorption spectra of Al2O3nanoparticles suspended in deionized water were recorded at room temperature using UV-visible spectroscopy. The absorption spectra show a strong peak at 210 nmarising from the presence of Al2O3nanoparticles. The results on absorption spectra are in good agreement with those investigated by XRD which confirmed the formation of Al2O3nanoparticles during the laser ablation of Al target in deionized water.

In Paper I of this series it was shown that high pressure interferometric measurements on a number of liquids reveal that the refractive index of liquids increases linearly with Eulerian strain even though the volume strain involved is as high as 33%. Further, it was also found that this linearity criterion can be used to discriminate between the various equations of state for liquids and that Keane's equation appears to be universally valid for all liquids. Having thus established the P-V relationship of liquids, the next problem of the refractive index-density relationship of liquids is considered in this article, The various equations prevalent in the literature--namely, Lorentz-Lorenz, Drude, Eykman, Onsager-Bottcher, Kirkwood-Brown, and Omini equations-are analyzed. The last two equations have been derived using a detailed statistical mechanical approach. It is found that none of these equations can predict the elastooptic behavior of liquids at high pressure quantitatively even though the latter two equations appear to yield values in reasonably good agreement with experimentally observed values.

No abstract