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Articles 1 - 6 of 6
Full-Text Articles in Condensed Matter Physics
Equilibrium Magnetic States In Individual Hemispherical Permalloy Caps, Robert Streubel, Volodymyr P. Kravchuk, Denis D. Sheka, Denys Makarov, Florian Kronast, Oliver G. Schmidt, Yuri Gaididei
Equilibrium Magnetic States In Individual Hemispherical Permalloy Caps, Robert Streubel, Volodymyr P. Kravchuk, Denis D. Sheka, Denys Makarov, Florian Kronast, Oliver G. Schmidt, Yuri Gaididei
Robert Streubel Papers
The magnetization distributions in individual soft magnetic permalloy caps on non-magnetic spherical particles with sizes ranging from 50 to 800nm are investigated. We experimentally visualize the magnetic structures at the resolution limit of the x-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM). By analyzing the so-called tail contrast in XMCD-PEEM, the spatial resolution is significantly enhanced, which allowed us to explore magnetic vortices and their displacement on curved surfaces. Furthermore, cap nanostructures are modeled as extruded hemispheres to determine theoretically the phase diagram of equilibrium magnetic states. The calculated phase diagram agrees well with the experimental observations. © 2012 American …
Investigation Of Vopcpho As An Acceptor Material For Bulk Heterojunction Solar Cells, Shahino Mah Abdullah
Investigation Of Vopcpho As An Acceptor Material For Bulk Heterojunction Solar Cells, Shahino Mah Abdullah
Shahino Mah Abdullah
In this study, we have successfully demonstrated a new system of donor–acceptor blend for bulk heterojunction solar cells of poly(3-hexylthiophene) (P3HT) by using vanadyl 2,9,16,23-tetraphenoxy-29H,31H-phthalocyanine (VOPcPhO) as acceptor material. A broad absorption over the whole visible range (450–750 nm) is achieved. Utilizing this blend system in solar cell fabrication, ITO/PEDOT:PSS/P3HT:VOPcPhO/Al solar cells have been fabricated and characterized in open air. A maximum power conversation efficiency up to 1.09% has been recorded. To confirm the charge transport, the electron and hole mobility of VoPcPhO has been measured. The results show that the VoPcPhO has bipolar transport and can act as an …
Magnetic Vortices On Closely Packed Spherically Curved Surfaces, Robert Streubel, Denys Makarov, Florian Kronast, Volodymyr Kravchuk, Manfred Albrecht, Oliver G. Schmidt
Magnetic Vortices On Closely Packed Spherically Curved Surfaces, Robert Streubel, Denys Makarov, Florian Kronast, Volodymyr Kravchuk, Manfred Albrecht, Oliver G. Schmidt
Robert Streubel Papers
We investigate the change of magnetic vortex states driven by curvature. The equilibrium state and magnetization reversal of soft magnetic permalloy (Py, Ni 80Fe 20) caps on self-assembled spherical particles with diameters of 100, 330, and 800 nm are investigated, revealing the vortex ground state for individual caps and closely packed cap arrays. The magnetic coupling between vortices is substantially reduced due to the shape of the cap as apparent in a much weaker dependence of the magnetization reversal process on the separation distance. Interestingly, the remaining coupling is still sufficiently large to introduce chirality frustrated vortex states …
Out-Of-Surface Vortices In Spherical Shells, Volodymyr P. Kravchuk, Denis D. Sheka, Robert Streubel, Denys Makarov, Oliver G. Schmidt, Yuri Gaididei
Out-Of-Surface Vortices In Spherical Shells, Volodymyr P. Kravchuk, Denis D. Sheka, Robert Streubel, Denys Makarov, Oliver G. Schmidt, Yuri Gaididei
Robert Streubel Papers
The interplay of topological defects with curvature is studied for out-of-surface magnetic vortices in thin spherical nanoshells. In the case of an easy-surface Heisenberg magnet it is shown that the curvature of the underlying surface leads to a coupling between the localized out-of-surface component of the vortex with its delocalized in-surface structure, i.e., polarity-chirality coupling. © 2012 American Physical Society.
Temperature-Sensitive Chemical Cell Based On Nickel (Ii) Phthalocyanine-Tetrasulfonic Acid Tetrasodium Salt, Shahino Mah Abdullah
Temperature-Sensitive Chemical Cell Based On Nickel (Ii) Phthalocyanine-Tetrasulfonic Acid Tetrasodium Salt, Shahino Mah Abdullah
Shahino Mah Abdullah
An organic compound Nickel (II) phthalocyanine-tetrasulfonic acid tetrasodium salt (NiTSPc) has been studied as a potential material for a solution based temperature sensor. Using NiTSPc, an ITO/NiTSPc solution/ITO chemical cell has been made and characterized in the temperature range of 20–85 ◦C. This sensor works on the principle of change in the resistance and capacitance of the chemical cell caused by the temperature variation. Good response/recovery and small hysteresis have been attained. The proposed sensor is aimed to evolve towards highly sensitive organic temperature sensor in a specific temperature range.
Qpced2.0: A Computer Program For The Processing And Quantification Of Polycrystalline Electron Diffraction Patterns, Xingzhong Li
Qpced2.0: A Computer Program For The Processing And Quantification Of Polycrystalline Electron Diffraction Patterns, Xingzhong Li
Nebraska Center for Materials and Nanoscience: Faculty Publications
The processing and quantification of electron diffraction patterns have become vital in advanced electron crystallographic analysis work. A computer program, QPCED2.0, has been developed for the handling of selected-area electron diffraction patterns for polycrystalline materials. QPCED2.0 can be used to enhance the visibility of electron diffraction patterns, to convert electron diffraction patterns into intensity profiles, and to retrieve precisely the lattice d spacings and the integral intensities of the diffraction rings. The design and implementation of QPCED2.0 are elucidated and application examples are given.