TY - JOUR A1 - Fritz, D. M. A1 - Reis, D. A. A1 - Adams, B. A1 - Akre, R. A. A1 - Arthur, J. A1 - Blome, Christian A1 - Bucksbaum, P. H. A1 - Cavalieri, A. L. A1 - Engemann, S. A1 - Fahy, S. A1 - Falcone, R. W. A1 - Fuoss, P. H. A1 - Gaffney, K. J. A1 - George, M. J. A1 - Hajdu, J. A1 - Hertlein, M. P. A1 - Hillyard, P. B. A1 - Horn-von Hoegen, Michael A1 - Kammler, Martin A1 - Kaspar, J. A1 - Kienberger, R. A1 - Krejcik, P. A1 - Lee, S. H. A1 - Lindenberg, A. M. A1 - McFarland, B. A1 - Meyer, D. A1 - Montagne, T. A1 - Murray, E. D. A1 - Nelson, A. J. A1 - Nicoul, Matthieu A1 - Pahl, R. A1 - Rudati, J. A1 - Schlarb, H. A1 - Siddons, D. P. A1 - Sokolowski-Tinten, Klaus A1 - Tschentscher, Th A1 - von der Linde, D. A1 - Hastings, J. B. T1 - Ultrafast bond softening in bismuth: mapping a solid's interatomic potential with X-rays JF - Science N2 - Intense femtosecond laser excitation can produce transient states of matter that would otherwise be inaccessible to laboratory investigation. At high excitation densities, the interatomic forces that bind solids and determine many of their properties can be substantially altered. Here, we present the detailed mapping of the carrier density-dependent interatomic potential of bismuth approaching a solid-solid phase transition. Our experiments combine stroboscopic techniques that use a high-brightness linear electron accelerator-based x-ray source with pulse-by-pulse timing reconstruction for femtosecond resolution, allowing quantitative characterization of the interatomic potential energy surface of the highly excited solid. Y1 - 2007 U6 - https://doi.org/10.1126/science.1135009 VL - 315 IS - 5812 SP - 633 EP - 636 PB - AAAS ER - TY - CHAP A1 - Sokolowski-Tinten, Klaus A1 - Blome, Christian A1 - Blums, Juris A1 - Shymanovich, Uladzimir A1 - Nicoul, Matthieu A1 - Cavalleri, Andrea A1 - Tarasevitch, A. A1 - Horn-von Hoegen, Michael A1 - Kammler, Martin A1 - von der Linde, Dietrich ED - Kobayashi, Tetsuro T1 - Ultrafast X-ray diffraction T2 - Ultrafast Phenomena XIV N2 - In the last few years the generation of femtosecond pulses in the X-ray regime has become possible. These ultrashort X-ray pulses have enabled femtosecond time- resolution to be extended to X-rays. Y1 - 2004 SN - 978-3-540-27213-7 U6 - https://doi.org/10.1007/3-540-27213-5_53 VL - 79 SP - 170 EP - 174 PB - Springer CY - Berlin, Heidelberg ER - TY - JOUR A1 - Kammler, Martin A1 - Horn- von Hoegen, Michael A1 - Voss, N. A1 - Tringides, Michael C. A1 - Menzel, Andreas A1 - Conrad, E. H. T1 - Si(001) step dynamics: A temporal low-energy electron diffraction study JF - Physical Review B N2 - We present equilibrium measurements of the dynamics of steps on Si(001) using temporal electron-diffraction spectroscopy. Activation energies and the rate limiting kinetics are identified for 950K<~T<~1130K. Unlike previous studies at higher temperatures, we can exclude evaporation and condensation of atoms or dimers from the step edges as the rate limiting process in this temperature regime. The possible reason for this difference is discussed in terms of a crossover from different rate-limiting kinetics. Y1 - 2002 U6 - https://doi.org/10.1103/PhysRevB.65.075312 VL - 65 IS - 7 PB - APS ER - TY - CHAP A1 - Navitski, Aliaksandr A1 - Serbun, Pavel A1 - Müller, Günter A1 - Schreiner, Rupert A1 - Dams, Florian T1 - Efficient and reliable field emission from silicon tip arrays for miniaturized electron sources T2 - 2011 24th International Vacuum Nanoelectronics Conference ; 18-22 July 2011 Wuppertal N2 - Silicon-based cathodes with precisely aligned field emitter arrays (FEA) applicable for miniaturized electron sources were successfully developed and fabricated. The cathode chips contain about 3×105 Si tips/cm2 in a triangular array with a tip height of 2.5 μm, tip radius of 20 nm, and lateral distance between tips of 20 μm. Amazingly homogeneous and well-aligned field emission (FE) from all tips (i.e. 100% efficiency) and maximum stable currents of typically 0.1 μA for p- and 0.6 μA for n-type Si were reproducibly achieved. Current-voltage characteristics of p-type Si tips exhibit the expected saturation at around 10 nA due to limited supply of electrons from a depletion layer, while the n-type Si tips show the usual FN behaviour. Additional coating of the Si tips with a 10 nm Au layer resulted in at least 5 times higher average FE current levels i.e. typically 3 μA but lead, however, to a 30% increase of the onset voltage. KW - cathodes KW - coatings KW - elemental semiconductors KW - field emission KW - field emitter arrays KW - miniaturized electron sources KW - silicon tips KW - structured cold cathode Y1 - 2011 UR - https://ieeexplore.ieee.org/document/6004567?arnumber=6004567 SN - 978-3-00-035081-8 SN - 978-1-4577-1243-2 SN - 2380-6311 SN - 2164-2370 SP - 71 EP - 72 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Pirker, Luka A1 - Ławrowski, Robert Damian A1 - Schreiner, Rupert A1 - Remškar, Maja A1 - Višić, Bojana T1 - MoₓWₓ₋₁S₂ Nanotubes for Advanced Field Emission Application JF - Advanced Functional Materials N2 - Transition metal dichalcogenide (TMDC) nanotubes complement the field of low-dimensional materials with their quasi-1D morphology and a wide set of intriguing properties. By introducing different transition metals into the crystal structure, their properties can be tailored for specific purpose and applications. Herein, the characterization and a subsequent preparation of single-nanotube field emission devices of MoxWx-1S2 nanotubes prepared via the chemical vapor transport reaction is presented. Energy-dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray diffraction indicate that the molybdenum and tungsten atoms are randomly distributed within the crystal structure and that the material is highly crystalline. High resolution transmission electron microscopy and electron diffraction (ED) patterns further corroborate these findings. A detailed analysis of the ED patterns from an eight-layer nanotube reveal that the nanotubes grow in the 2H structure, with each shell consists of one bilayer. The work function of the nanotubes is comparable to that of pure MoS2 and lower of pure WS2 NTs, making them ideal candidates for field emission applications. Two devices with different geometrical setup are prepared and tested as field emitters, showing promising results for single nanotube field emission applications. Y1 - 2023 U6 - https://doi.org/10.1002/adfm.202213869 SN - 1616-3028 N1 - Early View. Online Version of Record before inclusion in an issue SP - 1 EP - 8 PB - Wiley ER - TY - INPR A1 - Pangerl, Jonas A1 - Moser, Elisabeth A1 - Müller, Max A1 - Weigl, Stefan A1 - Jobst, Simon A1 - Rück, Thomas A1 - Bierl, Rudolf A1 - Matysik, Frank-Michael T1 - A Highly Sensitive Acetone and Ethanol Quantum Cascade Laser Based Photoacoustic Sensor: Characterization and Multi-Component Spectra Recording in Synthetic Breath T2 - SSRN Electronic Journal N2 - Trace gas analysis in breath is challenging due to the vast number of different components. We present a highly sensitive quantum cascade laser based photoacoustic setup for breath analysis. Scanning the range between 8260 and 8270 nm with a spectral resolution of 48 pm, we are able to quantify acetone and ethanol within a typical breath matrix containing water and CO2. We photoacoustically acquired spectra within this region of mid-infra-red light and prove that those spectra do not suffer from non-spectral interferences. The purely additive behavior of a breath sample spectrum was verified by comparing it with the independently acquired single component spectra using Pearson and Spearman correlation coefficients. A previously presented simulation approach is improved and an error attribution study is presented. With a 3σ detection limit of 6.5 ppbV in terms of ethanol and 250 pptV regarding acetone, our system is among the best performing presented so far. KW - Photoacoustic spectroscopy KW - quantum cascade laser KW - spectral simulation KW - breath analysis KW - acetone Y1 - 2022 U6 - https://doi.org/10.2139/ssrn.4305376 PB - Elsevier ER - TY - PAT A1 - Olbrich, Florian A1 - Pongratz, Christian A1 - Bierl, Rudolf A1 - Ehrlich, Ingo T1 - Method and System for Evaluating a Structural Integrity of an Aerial Vehicle Y1 - 2024 ER - TY - CHAP A1 - Peller, Sebastian A1 - Zankl, Tobias A1 - Fischer, Christoph A1 - Bierl, Rudolf T1 - Fast sound field characterization of beamforming capable capacitive micromachined ultrasonic transducer (CMUT) arrays by refracto-vibrometry T2 - IEEE IUS 2023, International Ultrasonics Symposium, Montréal, September 3-8, 2023 N2 - We introduce a time-optimized setup based on refracto-vibrometry for the purpose of scanning the sound field of capacitive micromachined ultrasonic transducer (CMUT) arrays primarily for the qualification of their beamforming capability. In comparison to commonly used microphones on a traversing stage the proposed method is substantially faster and consumes only a few minutes of time for a complete two-dimensional sound field containing about 100.000 scan points. T2 - Schnelle Schallfeld-Charakterisierung von CMUT-Arrays mithilfe von Refrakto-Vibrometrie KW - CMUT KW - LDV KW - refracto-vibrometry KW - sound field KW - beamforming Y1 - 2023 SN - 979-8-3503-4645-9 U6 - https://doi.org/10.1109/IUS51837.2023.10308126 SN - 1948-5727 SP - 1 EP - 3 PB - IEEE ER - TY - CHAP A1 - Herdl, Florian A1 - Bachmann, Michael A1 - Wohlfartsstätter, Dominik A1 - Düsberg, Felix A1 - Dudeck, Markus A1 - Eder, Magdalena A1 - Meyer, Manuel A1 - Pahlke, Andreas A1 - Edler, Simon A1 - Schels, Andreas A1 - Hansch, Walter A1 - Schreiner, Rupert A1 - Wohlfartsstatter, Dominik A1 - Dusberg, Felix T1 - A novel current dependent field emission performance test T2 - 2021 34th International Vacuum Nanoelectronics Conference (IVNC): 5-9 July 2021, Lyon, France N2 - A current dependent performance test for comparison of different field emitter arrays is introduced. Statistical analysis is enabled due to a short measurement time and as a main feature the electric field shift, comparable to the degradation of the emitter is examined. Significance of the test method is shown by a comparison of field emitter arrays with different doping levels. KW - Current measurement KW - Field emitter arrays KW - Statistical analysis KW - Systematics KW - Time measurement KW - Tools KW - Vacuum systems Y1 - 2021 U6 - https://doi.org/10.1109/IVNC52431.2021.9600695 SP - 1 EP - 2 ER - TY - CHAP A1 - Bieker, Johannes A1 - Roustaie, Farough A1 - Schlaak, Helmut F. A1 - Langer, Christoph A1 - Schreiner, Rupert T1 - Field emission characterization of in-situ deposited metallic nanocones T2 - 2017 30th International Vacuum Nanoelectronics Conference (IVNC), 10-14 July 2017, Regensburg, Germany N2 - An in-situ fabrication technique based on ion track etched template electrodeposition of metallic nanocones was used for the production of field emitter cathodes. Gold nanocones with a height of 24 microns, a base diameter between 3 to 4 microns and a tip diameter below 300 nanometers were deposited on a circular electrode with a diameter of 2.5 mm. The integral field emission (FE) measurements of samples with cone densities of 6 · 104 cones/cm2 (sample A) and 1 · 106 cones/cm2 (sample B) yielded in a maximum current of 37.5 μA at an applied field of 12.5 V/μm for sample A and 29.1 μA at 9.4 V/μm for sample B. The stability of emission current was investigated for over 48 hours and no degradation was observed. KW - CATHODES KW - Current measurement KW - FABRICATION KW - field emission KW - ion track template KW - Ions KW - Iron KW - nanocones KW - Vacuum technology KW - Voltage measurement Y1 - 2017 U6 - https://doi.org/10.1109/IVNC.2017.8051571 SP - 120 EP - 121 PB - IEEE ER -