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Full-Text Articles in Physics
Surfactant Properties Of Atmospheric And Model Humic‐Like Substances (Hulis), Ilya Taraniuk, Ellen Graber, Alexander Kostinski, Yinon Rudich
Surfactant Properties Of Atmospheric And Model Humic‐Like Substances (Hulis), Ilya Taraniuk, Ellen Graber, Alexander Kostinski, Yinon Rudich
Department of Physics Publications
Surface‐active organics such as humic‐like substances (HULIS) are abundant in aerosol particles and can lower the surface tension of cloud droplets forming on secondary organic and biomass burning aerosols. How fast is the diffusion of these species, relative to the time scale of cloud droplet growth? Here we report surface tension measurements of solutions containing HULIS extracted from smoke and pollution aerosol particles as well those of molecular weight‐fractionated aquatic fulvic acids. Diffusion coefficients are estimated based on the Gibbs adsorption isotherms. The results suggest that HULIS diffusion to the surface of forming droplets is typically more rapid than the …
Strain-Induced Formation Of Carbon And Boron Clusters In Boron Carbide During Dynamic Indentation, Dipankar Ghosh, Ghatu Subhash, Chee Huei Lee, Yoke Khin Yap
Strain-Induced Formation Of Carbon And Boron Clusters In Boron Carbide During Dynamic Indentation, Dipankar Ghosh, Ghatu Subhash, Chee Huei Lee, Yoke Khin Yap
Department of Physics Publications
The authors found that the level of amorphization or structural disorder in boron carbide is higher when induced by dynamic indentation compared to static indentation. Visible and uv Raman spectroscopies indicate that sp2-bonded aromatic carbon clusters were formed, consistent with the detected photoluminescence spectra. Infrared absorption shows that amorphous boron clusters were created by dynamic indentation which has strain rates ∼108 order higher than that introduced by static indentation. The decreased intensity of infrared stretching mode of carbon-boron-carbon (CBC) chains also suggests that amorphization is due to the collapse of B11C(CBC) unit cells, which reorganize …
Controlling Spin-Polarized Electron Transport Through A Molecule: The Role Of Molecular Conformation, L. Senapati, Ranjit Pati, S. C. Erwin
Controlling Spin-Polarized Electron Transport Through A Molecule: The Role Of Molecular Conformation, L. Senapati, Ranjit Pati, S. C. Erwin
Department of Physics Publications
We investigate theoretically the spin-polarized electron transport through a complex organic molecule coupled to magnetic contacts. Our focus is on how low-energy deformations of the molecule affect the current-voltage characteristics and the magnetotransport of this molecular-scale device. We find that fairly modest deformations, costing only a few tens of meVs, can substantially change the tunneling current—by factors of 2 or more. Such deformations have still larger impact on the magnetoresistance, with small changes in molecular conformation even leading to changes in the sign of the magnetoresistance.
Tuning The Ferromagnetism Of One-Dimensional Fe ∕ Pt ∕ Fe Multilayer Barcode Nanowires Via The Barcode Layer Effect, Puspamitra Panigrahi, Ranjit Pati
Tuning The Ferromagnetism Of One-Dimensional Fe ∕ Pt ∕ Fe Multilayer Barcode Nanowires Via The Barcode Layer Effect, Puspamitra Panigrahi, Ranjit Pati
Department of Physics Publications
Using first-principles density functional theory, we have predicted equilibrium structures and electronic and magnetic properties of one-dimensional ferromagnetic Fe∕Pt∕Fe multilayer barcode nanowires. By increasing the thickness of the Pt layer and consequently reducing the thickness of the Fe layer in the nanowire in the ferromagnetic configuration, we found that the average magnetic moment per iron atom, μav, increases monotonically with an ∼1∕N(Fe) dependence, where N(Fe) is the number of Fe layers. The monotonic increase in average magnetic moment is attributed to the change in magnetic moment at the Fe-Pt interface, and a simple model is …
Formation Of Single Crystalline Zno Nanotubes Without Catalysts And Templates, Samuel Mensah, Vijaya Kayastha, Ilia Ivanov, David Geohegan, Yoke Khin Yap
Formation Of Single Crystalline Zno Nanotubes Without Catalysts And Templates, Samuel Mensah, Vijaya Kayastha, Ilia Ivanov, David Geohegan, Yoke Khin Yap
Department of Physics Publications
Oxide and nitride nanotubes have gained attention for their large surface areas, wide energy band gaps, and hydrophilic natures for various innovative applications. These nanotubeswere either grown by templates or multistep processes with uncontrollable crystallinity. Here the authors show that single crystal ZnO nanotubes can be directly grown on planar substrates without using catalysts and templates. These results are guided by the theory of nucleation and the vapor-solid crystal growth mechanism, which is applicable for transforming other nanowires or nanorods into nanotubular structures.