Index of content:
Volume 110, Issue 4, 15 August 2011
110(2011); http://dx.doi.org/10.1063/1.3624596View Description Hide Description
We exploit unique infrared plasmonicabsorption properties of gold(Au)nanoparticles in the range of 2.5 to 20 μm. Fabrication of Au nanoplasmon particles with variable nanometer (nm) scale size and thickness gave us full control of tuning the absorption wavelength in the above infrared (IR) spectral regions. We did not observe polarization dependence for square size plasmon particles. However, by using plateau crescent (metal crescent structure with flat instead of rounded side on the top) metal particles we observed significant polarization effects in IR absorption spectra. We observed that the position of the absorption peak has linear dependence on the size of nanoparticles, and the absorption quantity depends on the density of the nanoparticles per unit area. The proposed nanoplasmon structure can be used to improve the performance of detector and light emitting diode(LED) devices operating in the IR region.
110(2011); http://dx.doi.org/10.1063/1.3622317View Description Hide Description
In the study, we introduced the local mean free path of phonons with boundary effects. The local thermal conductivity distribution from boundary to film bulk region was obtained, and the boundary scattering effect was examined by introducing a phonon Knudsen layer thickness. We calculated the ratio of effective thermal conductivity to the bulk one and the results are in agreement with available data.
Magnetodielectric response in 0.36BiScO3-0.64PbTiO3/La0.7Sr0.3MnO3 thin films and the corresponding model modifications110(2011); http://dx.doi.org/10.1063/1.3610421View Description Hide Description
Dielectric relaxation and magnetodielectric (MD) effects were observed in 0.36BiScO3-0.64PbTiO3/La0.7Sr0.3MnO3thin films. The universal dielectric response and distribution of relaxation time modifications were introduced into the Maxwell-Wagner (MW) model. Based on modified MW model, the negative MD response at low frequencies was attributed to magnetostriction of La0.7Sr0.3MnO3, while the large positive response at high frequencies mainly to the magnetoresistance of La0.7Sr0.3MnO3, and these two factors canceled each other out at intermediate frequencies. Moreover, a giant room temperature MD response of 9.5% was observed, and the linear MD response at 52 kHz was ascribed to the linear magnetoresistanceeffects.
110(2011); http://dx.doi.org/10.1063/1.3601870View Description Hide Description
The atomic and electronic structures at interfaces in thin films are typically different from the bulk and are vitally important in determining the physical properties of thin films. The interface between SrVO3, chosen as a prototype for vanadium-based perovskite materials in this work, and LaAlO3 substrate is investigated by scanning transmission electron microscopy, electron energy-loss spectroscopy, and theoretical multi-electron calculations. Extra electrons have been detected on the interface layer by comparing the energy-loss near-edge structures of V-L3,2 edges to those from the film far from the interface. Monochromated EELS and theoretical calculations for SrVO3, VO2, and V2O3 support this conclusion. The extra electrons appear to originate from a change in the local bonding configuration of V at the La-O terminated substrate surface as determined by Z-contrast imaging.