@inproceedings{9785, abstract = {{Hydrothermal method enables to synthesize high quality piezoelectric materials. To shorten the reaction time and to get higher quality materials, we propose an ultrasonic irradiation to the solution during the hydrothermal method. We named it ultrasonic assisted hydrothermal method (UAHTM). We have synthesized lead-free piezoelectric material and PZT thin film and the effect of UAHTM have been confirmed. In this study, we tried to improve UAHTM. First, to generate powerful and stable ultrasonic irradiation at high temperature on UAHTM, we developed a new transducer using LiNbO3 single crystal. Second, to prevent contamination to the materials, A Teflon cover on the tip of transducer was attached.}}, author = {{Isobe, Gaku and Ageba, Ryo and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, booktitle = {{AIP Conference Proceedings}}, editor = {{B. J. Linde, Bogumil and Paczkowski, Jacek and Ponikwicki, Nikodem}}, keywords = {{contamination, lead compounds, piezoelectric materials, piezoelectric thin films, piezoelectric transducers, ultrasonic effects}}, number = {{1}}, pages = {{569--572}}, publisher = {{AIP}}, title = {{{Synthesis of piezoelectric materials by ultrasonic assisted hydrothermal method}}}, doi = {{10.1063/1.3703251}}, volume = {{1433}}, year = {{2012}}, } @article{9786, abstract = {{Self-optimizing mechatronic systems are a new class of technical systems. On the one hand, new challenges regarding dependability arise from their additional complexity and adaptivity. On the other hand, their abilities enable new concepts and methods to improve the dependability of mechatronic systems. This paper introduces a multi-level dependability concept for selfoptimizing mechatronic systems and shows how probabilistic planning can be used to improve the availability and reliability of systems in the operating phase. The general idea to improve the availability of autonomous systems by applying probabilistic planning methods to avoid energy shortages is exemplified on the example of an innovative railway vehicle.}}, author = {{Klöpper, Benjamin and Sondermann-Wölke, Christoph and Romaus, Christoph}}, journal = {{Journal of Robotics and Mechatronics}}, keywords = {{self-optimizing systems, dependability, probabilistic planning, energy management}}, number = {{1}}, pages = {{5--15}}, title = {{{Probabilistic Planning for Predictive Condition Monitoring and Adaptation Within the Self-Optimizing Energy Management of an Autonomous Railway Vehicle}}}, volume = {{24}}, year = {{2012}}, } @inproceedings{9787, author = {{Kohl, Sergej and Sextro, Walter and Zuber, Armin}}, booktitle = {{8. Tag des Fahrwerks, Aachen, 2012}}, pages = {{38--60}}, title = {{{Benteler Vehicle Dynamics -- Fahrdynamikentwicklung basierend auf einer neuen Auslegungstheorie}}}, year = {{2012}}, } @inproceedings{9788, abstract = {{A hydrothermal method utilizes a crystallization process in the solution so that the pure and high-quality powders can be realized. Sintering from the hydrothermal KNbO3 and NaNbO3 powders, a high-dense lead-free piezoelectric (K,Na)NbO3 ceramics could be obtained (density: 98.8\%). Concerning about the g33 constant, high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal (K,Na)NbO3 ceramics is usable for the sensors and the energy harvesting devices. To demonstrate the (K,Na)NbO3 ceramics, a hydrophone sensor was fabricated and evaluated.}}, author = {{Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}}, booktitle = {{Ultrasonics Symposium (IUS), 2012 IEEE International}}, issn = {{1948-5719}}, keywords = {{crystallisation, hydrophones, piezoceramics, potassium compounds, powder technology, powders, sensors, sintering, sodium compounds, (K0.48Na0.52)NbO3, KNbO3 powder, NaNbO3 powder, crystallization, energy harvesting devices, g33 constant, hydrophone sensor, hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics, hydrothermal method, piezoelectric applications, sintering, Materials, Transducers}}, pages = {{194--195}}, title = {{{Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics}}}, doi = {{10.1109/ULTSYM.2012.0048}}, year = {{2012}}, } @article{9789, abstract = {{[$Li_x(Na_0.52K_0.48)_1-x]NbO_3 (0 \leq x \leq 0.091)$ ceramics were synthesized using hydrothermal powders and the lithium doping content was controlled to optimize their piezoelectric properties. The raw KNbO$_3$ and NaNbO$_3$ powders were obtained separately by a hydrothermal method and LiNbO$_3$ powders were prepared by milling a commercial LiNbO$_3$ single crystal. These powders were mixed with ethanol at a molar ratio LiNbO$_3$: ($Na_0.52K_0.48$)NbO$_3 = x : 1-x$. The synthesized powders were sintered at 1060--1120 $\,^{\circ}$C for 2 h. We succeeded in obtaining highly dense [$Li_x(Na_0.52K_0.48)_1-x]NbO_3$ ceramics using hydrothermal powder. The X-ray diffraction patterns revealed that the crystal phase changed from orthorhombic to tetragonal at around x = 0.06. At this morphotropic phase boundary (MPB), the c/a ratio changed from 1.016 to 1.024 and the highest piezoelectric constant was obtained with the chemical component of [$Li_x(Na_0.52K_0.48)_1-x]NbO_3$. The obtained piezoelectric properties were as follows: $k_33 = 0.51, \epsilon 33^T/ \epsilon _0 = 836$ , $c_33^E = 46$ GPa, $d_33 = 203$ pC/N, and $T_c = 482 $\,^{\circ}$C$.}}, author = {{Maeda, Takafumi and Hemsel, Tobias and Morita, Takeshi}}, journal = {{Japanese Journal of Applied Physics}}, pages = {{09MD08}}, publisher = {{The Japan Society of Applied Physics}}, title = {{{Piezoelectric Properties of Li-Doped (K0.48Na0.52)NbO3 Ceramics Synthesized Using Hydrothermally-Derived KNbO3 and NaNbO3 Fine Powders}}}, doi = {{10.1143/JJAP.51.09MD08}}, volume = {{51}}, year = {{2012}}, } @inproceedings{9791, abstract = {{The rapid development of communication and information technology opens up fascinating perspectives, which go far beyond the state of the art in mechatronics: mechatronic systems with inherent partial intelligence. These so called self-optimizing systems adapt their objectives and behavior autonomously and flexibly to changing operating conditions. On the one hand, securing the dependability of such systems is challenging due to their complexity and non-deterministic behavior. On the other hand, self-optimization can be used to increase the dependability of the system during its operation. However, it has to be ensured, that the self-optimization works dependable itself. To cope with these challenges, the multi-level dependability concept was developed. It enables predictive condition monitoring, influences the objectives of the system and determines suitable means to improve the system's dependability during its operation. In this contribution we introduce a procedure for the conceptual design of an advanced condition monitoring based on the system's principle solution. The principle solution describes the principal operation mode of the system and its desired behavior. It is modeled using the specification technique for the domain-spanning description of the principle solution of a self-optimizing system and consists of a coherent system of eight partial models (e.g. requirements, active structure, system of objectives, behavior, etc.). The partial models are analyzed separately in order to derive the components of the multi-level dependability concept. In particular, the reliability analysis of the partial model active structure is performed to identify the system elements to be monitored and parameters to be measured. The principle solution is extended accordingly: e.g. with system elements required for the realization of the dependability concept. The advantages of the method are shown on the self-optimizing guidance module of a railroad vehicle.}}, author = {{Sondermann-Wölke , Christoph and Meyer, Tobias and Dorociak, Rafal and Gausemeier, Jürgen and Sextro, Walter}}, booktitle = {{Proceedings of the 11th International Probabilistic Safety Assessment and Management Conference (PSAM11) and The Annual European Safety and Reliability Conference (ESREL2012)}}, keywords = {{Mechatronic Systems, Principle Solution, Condition Monitoring, Conceptual Design}}, title = {{{Conceptual Design of Advanced Condition Monitoring for a Self-Optimizing System based on its Principle Solution}}}, year = {{2012}}, } @article{9806, abstract = {{Piezoelectric inertia motors, also known as ``stick-slip-drives'', use the inertia of a body to drive it by means of a friction contact in small steps. While these steps normally involve stiction and sliding, the motors can also operate in ``slip-slip'' mode without any phase of static friction. In this contribution, a one degree of freedom model of an inertia motor driven by an ideal actuator is analysed. Start-up and constant velocity operation of the motor are investigated and appropriate quantities to compare ``stick-slip'' and ``slip-slip'' operation are determined. Different aspects such as velocity, uniformity of motion, load capacity, robustness, efficiency, and wear are considered. The analysis allows both modes to be applied advantageously in different applications and can widen the field of application of piezoelectric inertia motors. Motor designers are enabled to choose the appropriate mode of operation and the best drive parameters for their individual applications.}}, author = {{Hunstig, Matthias and Hemsel, Tobias and Sextro, Walter}}, journal = {{ACTUATOR 2012 Conference Proceedings}}, keywords = {{Piezoelectric Inertia Motors, Drive Signals, Stick-slip, Slip-slip}}, pages = {{761--764}}, title = {{{Analysis of different operation modes for inertia motors}}}, year = {{2012}}, } @article{4095, abstract = {{Aiming to diminish the reflection losses of glass covered light harvesting devices, the optical reflectivity of nanostructured glass surfaces is studied theoretically and experimentally. The work is inspired by the nanoscale roughness of insect eyes, which is tried to be replicated on a technical glass surface. To this end, the reflectivity of glass surfaces with topographies represented by linear, parabolic and Fermishaped glass/air fill factor profiles is calculated for normal incidence. It is shown that using the latter ones, an almost complete suppression of reflections can be achieved. A simple, self-organization technique to create such Fermi-shaped filling factor profiles in glass experimentally is also presented.}}, author = {{Achtelik, J. and Sievers, W. and Lindner, Jörg}}, issn = {{0921-5107}}, journal = {{Materials Science and Engineering: B}}, location = {{Straßburg (France)}}, number = {{9}}, pages = {{635--638}}, publisher = {{Elsevier BV}}, title = {{{Biomimetic approaches to create anti-reflection glass surfaces for solar cells using self-organizing techniques}}}, doi = {{10.1016/j.mseb.2012.10.014}}, volume = {{178}}, year = {{2012}}, } @article{4104, abstract = {{We report on the molecular beam epitaxy growth of cubic GaN on 3C–SiC (001) nanostructures. Transmission electron microscopy (TEM) studies show phase-pure cubic GaN crystals with a low defect density on top of the post shaped 3C–SiC nanostructures and GaN grown on their sidewalls, which is dominated by {111} planar defects. The nanostructures, aligned parallel and perpendicular to the [110] directions of the substrate, are located in anti-phase domains of the 3C–SiC/Si (001) substrate. These anti-phase domains strongly influence the optimum growth of GaN layers in these regions. TEM measurements demonstrate a different stacking fault density in the cubic GaN epilayer in these areas.}}, author = {{Kemper, R.M. and Hiller, L. and Stauden, T. and Pezoldt, J. and Duschik, K. and Niendorf, T. and Maier, H.J. and Meertens, D. and Tillmann, K. and As, D.J. and Lindner, Jörg}}, issn = {{0022-0248}}, journal = {{Journal of Crystal Growth}}, location = {{Nara (Japan)}}, pages = {{291--294}}, publisher = {{Elsevier BV}}, title = {{{Growth of cubic GaN on 3C–SiC/Si (001) nanostructures}}}, doi = {{10.1016/j.jcrysgro.2012.10.011}}, volume = {{378}}, year = {{2012}}, } @article{4114, abstract = {{Two methods to create biomimetic anti-reflection nanostructures in ordinary glass microscope object slides are presented. One technique is based on a nanosphere lithography process combined with physical vapour deposition of nickel and reactive ion etching (RIE). The other uses plasma induced dewetting of a smooth nickel surface. The amount of reflected light was measured and a method to simulate the reflectivity from an atomic force microscopy (AFM) topography scan of the glass surface is presented. The reflectivity for visible light at normal incidence was reduced to 20-50 % of the original value with both methods and the simulation gives results in good agreement to the measurement.}}, author = {{Achtelik, Jörn and Kemper, Ricarda M. and Sievers, Werner and Lindner, Jörg}}, issn = {{1946-4274}}, journal = {{MRS Proceedings}}, location = {{Boston (USA)}}, publisher = {{Cambridge University Press (CUP)}}, title = {{{Self-Organized Nanostructure Formation for Anti-Reflection Glass Surfaces}}}, doi = {{10.1557/opl.2012.491}}, volume = {{1389}}, year = {{2012}}, } @inproceedings{4115, author = {{Brodehl, Christoph and Greulich-Weber, Siegmund and Lindner, Jörg}}, location = {{Paderborn}}, title = {{{Gyrotropic Metamaterials}}}, year = {{2012}}, } @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{4133, author = {{Kemper, R.M. and Hiller, L. and Stauden, T. and Pezoldt, J. and Meertens, D. and Luysberg, M. and Tillmann, K. and Riedl, Thomas and As, Donald and Lindner, Jörg}}, location = {{Manchester (UK)}}, title = {{{TEM investigation of GaN thin films grown on nanostructured 3C-SiC/Si(001) substrates}}}, year = {{2012}}, } @inproceedings{4134, author = {{Lindner, Jörg}}, location = {{Warsaw (Poland)}}, title = {{{Nanosphere Lithography: State-of-the-art and Future Directions}}}, year = {{2012}}, } @inproceedings{4135, author = {{Pauly, Johannes and Lindner, Jörg}}, location = {{Warsaw (Poland)}}, title = {{{TEM Characterization of Nickel Nanodot Arrays on Silicon formed by Nanosphere Lithography}}}, year = {{2012}}, } @inproceedings{4138, author = {{Lindner, Jörg}}, location = {{Oberkochen und Jena (online)}}, title = {{{Nanokugellithographie: Grundlagen und Anwendungen}}}, year = {{2012}}, } @inproceedings{4139, author = {{Lindner, Jörg}}, location = {{Leipzig (Germany)}}, title = {{{Nanolithographie von Oberflächen für das Wachstum optoelektronischer Strukturen}}}, year = {{2012}}, } @article{43, author = {{Chen, Xianzhong and Huang, Lingling and Mühlenbernd, Holger and Li, Guixin and Bai, Benfeng and Tan, Qiaofeng and Jin, Guofan and Qiu, Cheng-Wei and Zhang, Shuang and Zentgraf, Thomas}}, issn = {{2041-1723}}, journal = {{Nature Communications}}, publisher = {{Springer Nature}}, title = {{{Dual-polarity plasmonic metalens for visible light}}}, doi = {{10.1038/ncomms2207}}, volume = {{3}}, year = {{2012}}, } @article{4333, author = {{Feneberg, Martin and Röppischer, Marcus and Cobet, Christoph and Esser, Norbert and Schörmann, Jörg and Schupp, Thorsten and As, Donat Josef and Hörich, Florian and Bläsing, Jürgen and Krost, Alois and Goldhahn, Rüdiger}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{15}}, publisher = {{American Physical Society (APS)}}, title = {{{Optical properties of cubic GaN from 1 to 20 eV}}}, doi = {{10.1103/physrevb.85.155207}}, volume = {{85}}, 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}}, }