@article{4131, abstract = {{We report an anisotropic formation of defects in cubic GaN grown on nano-patterned 3C-SiC/Si (001) by molecular beam epitaxy. Nano-patterning of 3C-SiC/Si (001) is achieved by nanosphere lithography and a reactive ion etching process. Atomic force microscopy and scanning electron microscopy show that the selectivearea- grown cubic GaN nucleates in two structurally different domains, which most probably originate from the substrate. In adjacent domains the formation of defects, especially hexagonal inclusions, is different and leads to two different surface morphologies. The dominant phase within these domains was measured by electron backscatter diffraction. Optical properties were investigated by micro-photoluminescence and cathodoluminescence spectroscopy.}}, author = {{Kemper, R. M. and Häberlen, M. and Schupp, T. and Weinl, M. and Bürger, M. and Ruth, M. and Meier, Cedrik and Niendorf, T. and Maier, H. J. and Lischka, K. and As, D. J. and Lindner, Jörg}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, number = {{3-4}}, pages = {{1028--1031}}, publisher = {{Wiley}}, title = {{{Formation of defects in cubic GaN grown on nano-patterned 3C-SiC (001)}}}, doi = {{10.1002/pssc.201100174}}, volume = {{9}}, year = {{2012}}, } @inproceedings{4380, abstract = {{The structural and vibrational properties of lithium niobate (LN) – lithium tantalate (LT) mixed crystals (LNT, LiNb1-xTaxO3) are investigated over the whole composition range by first-principles simulations. The crystal volume grows roughly linearly from LT to LN, whereby the lattice parameters a and c show minor deviations from the Vegard behavior between the end compounds, LiNbO3 and LiTaO3. Our calculations in the framework of the density functional theory show the TO1, TO2 and TO4-modes to become harder with increasing Nb concentration. TO3 becomes softer with increasing Nb content, instead. The frequency shifts of the zone center A1-TO phonon modes for crystals with different compositions are found to be as large as 30 cm-1. Raman spectroscopy, which is sensitive to the A1 modes, can be therefore employed to determine the crystal composition.}}, author = {{Sanna, Simone and Riefer, Arthur and Neufeld, Sergej and Schmidt, Wolf Gero and Berth, Gerhard and Widhalm, Alex and Zrenner, Artur}}, booktitle = {{Proceedings of ISAF-ECAPD-PFM 2012}}, keywords = {{Ferroelectrics, Vibrational properties, LiNbO3, LiTaO3, Mixed Crystals}}, location = {{Aveiro, Portugal}}, title = {{{Vibrational fingerprints of LiNbO3-LiTaO3 mixed crystals}}}, year = {{2012}}, } @inbook{4381, abstract = {{Coherent physics and applications of exciton qubits in electric fi eld tunable quantum dot structures are our focus. Excitations with picosecond (ps) laser pulses result in qubit rotations. Using state projection by tunnelling the readout can be performed in quantitative way. As a function of electric fi eld induced detuning Ramsey fringes of a single exciton qubit can be observed and controlled for double pulse excitation. Therefore it is possible to demonstrate voltage controlled qubit manipulations within a wide range of pulse delays. Using fast electric signals, phase-locked to ps-laser pulses, the coherent control of an exciton qubit can be obtained by electric interaction. Such voltage controlled qubit manipulations seem to be essential for new types of optoelectronic quantum gates and novel applications in the fi eld of coherent optoelectronics.}}, author = {{Michaelis de Vasconcellos, Steffen and Gordon, Simon and Mantei, Dirk and Leier, Yves Alexander and Al-Hmoud, M. and Quiring, Wadim and Zrenner, Artur}}, booktitle = {{QUANTUM OPTICS WITH SEMICONDUCTOR NANOSTRUCTURES}}, editor = {{Jahnke, Frank}}, isbn = {{9780857092328 0857092324}}, keywords = {{excitons, quantum bits, coherent manipulation, Ramsey interference, quantum gate}}, pages = {{528--559}}, publisher = {{Woodhead Publishing}}, title = {{{Coherent optoelectronics with quantum dots}}}, year = {{2012}}, } @article{1711, author = {{Huang, Lingling and Chen, Xianzhong and Mühlenbernd, Holger and Li, Guixin and Bai, Benfeng and Tan, Qiaofeng and Jin, Guofan and Zentgraf, Thomas and Zhang, Shuang}}, issn = {{1530-6984}}, journal = {{Nano Letters}}, number = {{11}}, pages = {{5750--5755}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Dispersionless Phase Discontinuities for Controlling Light Propagation}}}, doi = {{10.1021/nl303031j}}, volume = {{12}}, year = {{2012}}, } @article{1712, author = {{Ye, Ziliang and Zhang, Shuang and Wang, Yuan and Park, Yong-Shik and Zentgraf, Thomas and Bartal, Guy and Yin, Xiaobo and Zhang, Xiang}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{15}}, publisher = {{American Physical Society (APS)}}, title = {{{Mapping the near-field dynamics in plasmon-induced transparency}}}, doi = {{10.1103/physrevb.86.155148}}, volume = {{86}}, year = {{2012}}, } @article{1713, author = {{Liu, Yongmin and Palomba, Stefano and Park, Yongshik and Zentgraf, Thomas and Yin, Xiaobo and Zhang, Xiang}}, issn = {{1530-6984}}, journal = {{Nano Letters}}, number = {{9}}, pages = {{4853--4858}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Compact Magnetic Antennas for Directional Excitation of Surface Plasmons}}}, doi = {{10.1021/nl302339z}}, volume = {{12}}, year = {{2012}}, } @article{1714, author = {{Lanzillotti-Kimura, N. D. and Zentgraf, Thomas and Zhang, X.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{4}}, publisher = {{American Physical Society (APS)}}, title = {{{Control of plasmon dynamics in coupled plasmonic hybrid mode microcavities}}}, doi = {{10.1103/physrevb.86.045309}}, volume = {{86}}, year = {{2012}}, } @article{1715, author = {{Ishikawa, Atsushi and Oulton, Rupert F. and Zentgraf, Thomas and Zhang, Xiang}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{15}}, publisher = {{American Physical Society (APS)}}, title = {{{Slow-light dispersion by transparent waveguide plasmon polaritons}}}, doi = {{10.1103/physrevb.85.155108}}, volume = {{85}}, year = {{2012}}, } @article{15981, author = {{Tröster, Thomas and Marten, Thorsten and Thomas, Dieter and Block, Holger and Lauter, Christian and Thöne, Markus}}, journal = {{Forschungsforum Paderborn}}, number = {{15/2012}}, pages = {{30--38}}, publisher = {{Universität Paderborn}}, title = {{{Automobilleichtbau mit innovativen Werkstoffen und Prozessen}}}, volume = {{15}}, year = {{2012}}, } @article{15983, author = {{Lauter, Christian and Werneke, Simon and Siewers, Bernd and Tröster, Thomas}}, issn = {{1865-4819}}, journal = {{Lightweight Design}}, pages = {{53--58}}, title = {{{Endkonturennahe Fertigung von höchstfesten Hybridbauteilen}}}, doi = {{10.1365/s35725-012-0079-2}}, year = {{2012}}, } @inproceedings{15985, author = {{Reuter, Corin and Frantz, Meike and Lauter, Christian and Block, Holger and Tröster, Thomas}}, location = {{Turin, Italy}}, title = {{{Simulation and testing of hybrid structures consisting of press-hardened steel and CFRP}}}, year = {{2012}}, } @inproceedings{15987, author = {{Lauter, Christian and Frantz, Meike and Kohler, J. P. and Tröster, Thomas}}, location = {{Venice, Italy}}, title = {{{Crash tests of hybrid structures consisting of sheet metal and local CFRP reinforcements}}}, year = {{2012}}, } @inproceedings{15988, author = {{Lauter, Christian and Sarrazin, M. and Tröster, Thomas}}, location = {{Porto, Portugal}}, title = {{{Joining technologies for hybrid materials consisting of sheet metal and carbon fibre reinforced plastics}}}, year = {{2012}}, } @article{15989, author = {{Ickert, Leif and Thomas, Dieter and Tröster, Thomas and Eckstein, Lutz}}, issn = {{2192-7863}}, journal = {{FAT-Schriftenreihe 244}}, number = {{244}}, publisher = {{Forschungsvereinigung Automobiltechnik e.V.}}, title = {{{Beitrag zum Fortschritt im Automobilleichtbau durch belastungsgerechte Gestaltung und innovative Lösungen für lokale Verstärkungen von Fahrzeugstrukturen in Mischbauweise}}}, year = {{2012}}, } @inproceedings{16004, author = {{Lauter, Christian and Siewers, Bernd and Zanft, B. and Tröster, Thomas}}, location = {{Porto }}, title = {{{Crash worthiness of hybrid pillar structures consisting of sheet metal and local CFRP reinforcements}}}, year = {{2012}}, } @inproceedings{16007, author = {{Thöne, M. and Leuders, S. and Riemer, A. and Tröster, Thomas and Richard, H. A.}}, location = {{Austin, Texas, USA}}, title = {{{Influence of heat-treatment on Selective Laser Melting products - e.g. Ti6Al4V}}}, year = {{2012}}, } @article{16008, author = {{Riemer, A. and Leuders, S. and Tröster, Thomas and Richard, H. A.}}, journal = {{DVM-Bericht 139, Werkstoffe und Fügeverfahren - Neue Herausforderungen für die Betriebsfestigkeit}}, publisher = {{Deutscher Verband für Materialforschung und -prüfung e.V.}}, title = {{{Untersuchung zyklisch belasteter SLM-Bauteile aus der Titan-Aluminium-Legierung TiAl6V4}}}, year = {{2012}}, } @inproceedings{16009, author = {{Leuders, S. and Riemer, A. and Tröster, Thomas and Richard, H. A.}}, location = {{Kassel}}, title = {{{Characterization and Comparison of Mechanical Properties of SLM Materials with Regard to Process Cycle Time Improvement}}}, year = {{2012}}, } @article{16015, author = {{Leuders, S. and Thöne, M. and Riemer, A. and Niendorf, T. and Tröster, Thomas and Richard, H.A. and Maier, H.J.}}, issn = {{0142-1123}}, journal = {{International Journal of Fatigue}}, pages = {{300--307}}, title = {{{On the mechanical behaviour of titanium alloy TiAl6V4 manufactured by selective laser melting: Fatigue resistance and crack growth performance}}}, doi = {{10.1016/j.ijfatigue.2012.11.011}}, year = {{2012}}, } @inproceedings{22164, abstract = {{Generative production techniques have the advantage of manufacturing parts via an additive process without needing a forming tool. One of these additive manufacturing technologies is "Fused Deposition Modeling" (FDM). It is one of the most used additive manufacturing processes to produce prototypes and end-use parts. From a 3D-CAD data set, components and assemblies are manufactured out of thermoplastic material layer by layer by means of an additive process. An extrusion head deposits the molten thermoplastic filament to create each layer with a particular tool path. Due to the thermal fusion the material bonds with the layer beneath and solidifies. Thus a permanent bonding of two layers is formed. In this paper the mechanical data of parts, manufactured with the system Fortus 400mc from Stratasys with the material Ultem*9085 are presented. Tensile and flexural tests according to both, the ASTM and the ISO standard, are conducted. Test specimens are generated with the standard parameters of the native software in different build directions. The tests show different strength and strain characteristics that depend on the given structure as a result of the build direction. Furthermore tensile specimens according to the ASTM standard are generated with changed parameters of the native software to increase the mechanical strength properties. The results are compared to injection molded strength properties.}}, author = {{Bagsik, A. and Schöppner, Volker and Klemp, E.}}, booktitle = {{1st International Conference on Thermo-Mechanically Graded Materials}}, isbn = {{9783942267588}}, pages = {{129--134}}, title = {{{Tensile and Flexural Properties of Fused Deposition Modeling Parts Manufactured with ULTEM*9085}}}, volume = {{1}}, year = {{2012}}, }