@article{59269,
  abstract     = {{Ferroelectric materials play a crucial role in a broad range of technologies due to their unique properties that are deeply connected to the pattern and behavior of their ferroelectric (FE) domains. Chief among them, barium titanate (BaTiO3; BTO) sees widespread applications such as in electronics but equally is a ferroelectric model system for fundamental research, e.g., to study the interplay of such FE domains, the domain walls (DWs), and their macroscopic properties, owed to BTO’s multiple and experimentally accessible phase transitions. Here, we employ Second Harmonic Generation Microscopy (SHGM) to in situ investigate the cubic-to-tetragonal (at ∼126°C) and the tetragonal-to-orthorhombic (at ∼5°C) phase transition in single-crystalline BTO via three-dimensional (3D) DW mapping. We demonstrate that SHGM imaging provides the direct visualization of FE domain switching as well as the domain dynamics in 3D, shedding light on the interplay of the domain structure and phase transition. These results allow us to extract the different transition temperatures locally, to unveil the hysteresis behavior, and to determine the type of phase transition at play (first/second order) from the recorded SHGM data. The capabilities of SHGM in uncovering these crucial phenomena can easily be applied to other ferroelectrics to provide new possibilities for in situ engineering of advanced ferroic devices.}},
  author       = {{Kirbus, Benjamin and Seddon, Samuel D. and Kiseleva, Iuliia and Beyreuther, Elke and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  number       = {{15}},
  publisher    = {{AIP Publishing}},
  title        = {{{Probing ferroelectric phase transitions in barium titanate single crystals via in-situ second harmonic generation microscopy}}},
  doi          = {{10.1063/5.0237769}},
  volume       = {{136}},
  year         = {{2024}},
}

@article{59271,
  abstract     = {{Lithium niobate (LNO) and lithium tantalate (LTO) see widespread use in fundamental research and commercial technologies reaching from electronics over classical optics to integrated quantum communication. The mixed crystal system lithium niobate tantalate (LNT) allows for the dedicate engineering of material properties by combining the advantages of the two parental materials LNO and LTO. Vibrational spectroscopies such as Raman spectroscopy or (Fourier transform) infrared (IR) spectroscopy are vital techniques to provide detailed insight into the material properties, which is central to the analysis and optimization of devices. This work presents a joint experimental–theoretical approach allowing to unambiguously assign the spectral features in the LNT material family through both Raman and IR spectroscopy, as well as providing an in‐depth explanation for the observed scattering efficiencies based on first‐principles calculations. The phononic contribution to the static dielectric tensor is calculated from the experimental and theoretical data using the generalized Lyddane–Sachs–Teller relation and compared with the results of the first‐principles calculations.}},
  author       = {{Bernhardt, Felix and Gharat, Soham and Kapp, Alexander and Pfeiffer, Florian and Buschbeck, Robin and Hempel, Franz and Pashkin, Oleksiy and Kehr, Susanne C. and Rüsing, Michael and Sanna, Simone and Eng, Lukas M.}},
  issn         = {{1862-6300}},
  journal      = {{physica status solidi (a)}},
  number       = {{1}},
  pages        = {{2300968}},
  publisher    = {{Wiley}},
  title        = {{{Lattice Dynamics of LiNb(1–x)Ta(x)O3 Solid Solutions: Theory and Experiment}}},
  doi          = {{10.1002/pssa.202300968}},
  volume       = {{222}},
  year         = {{2024}},
}

@article{59270,
  abstract     = {{Lithium niobate tantalate (LiNb1−xTaxO3, LNT) solid solutions offer exciting new possibilities for applications ranging from optics, piezotronics, and electronics beyond the capabilities of the widely used singular compounds of lithium niobate (LiNbO3, LN) or lithium tantalate (LiTaO3, LT). Crystal growth of homogeneous LNT single crystals by the Czochralski method is still challenging. One key aspect of homogeneous growth is the accurate knowledge of thermal conductivity through the crystal boule during the growth, which is central to control the crystal growth. Therefore, the temperature dependent thermal conductivity of pure LN, LT, and LNT solid solutions, as well as of selected doped LN and LT crystals (Mg, Zn) was investigated across the temperature range from 300 to 1300 K. The results that span across the whole composition range can directly be applied for optimizing growth conditions of both LNT solid solutions as well as doped and undoped LN and LT crystals.}},
  author       = {{Bashir, Umar and Rüsing, Michael and Klimm, Detlef and Blukis, Roberts and Koppitz, Boris and Eng, Lukas M. and Bickermann, Matthias and Ganschow, Steffen}},
  issn         = {{0925-8388}},
  journal      = {{Journal of Alloys and Compounds}},
  publisher    = {{Elsevier BV}},
  title        = {{{Thermal conductivity in solid solutions of lithium niobate tantalate single crystals from 300 K up to 1300 K}}},
  doi          = {{10.1016/j.jallcom.2024.176549}},
  volume       = {{1008}},
  year         = {{2024}},
}

@article{59272,
  abstract     = {{Ferroelectrics such as LiNbO3 (LN) are wide-band-gap insulators that may show a high local electric conductivity at the domain walls (DWs). The latter are interfaces separating regions of noncollinear polarization, which can be manipulated to build integrated nanoelectronic elements. In the present work, we model different DW types in LN from first principles. Our models reveal the DW morphology and shed light on their electronic properties: A strong band bending is predicted for charged DWs, leading to local metallicity. Defect trapping at the DW may further enhance the electric conductivity.}},
  author       = {{Verhoff, Leonard M. and Pionteck, Mike N. and Rüsing, Michael and Fritze, Holger and Eng, Lukas M. and Sanna, Simone}},
  issn         = {{2643-1564}},
  journal      = {{Physical Review Research}},
  number       = {{4}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Two-dimensional electronic conductivity in insulating ferroelectrics: Peculiar properties of domain walls}}},
  doi          = {{10.1103/physrevresearch.6.l042015}},
  volume       = {{6}},
  year         = {{2024}},
}

@article{59273,
  abstract     = {{Ferroelectric domain walls (DWs) are promising structures for assembling future nano-electronic circuit elements on a larger scale since reporting domain wall currents of up to 1 mA per single DW. One key requirement hereto is their reproducible manufacturing by gaining preparative control over domain size and domain wall conductivity (DWC). To date, most works on DWC have focused on exploring the fundamental electrical properties of individual DWs within single-shot experiments, with an emphasis on quantifying the origins of DWC. Very few reports exist when it comes to comparing the DWC properties between two separate DWs, and literally nothing exists where issues of reproducibility in DWC devices have been addressed. To fill this gap while facing the challenge of finding guidelines for achieving predictable DWC performance, we report on a procedure that allows us to reproducibly prepare single hexagonal domains of a predefined diameter into uniaxial ferroelectric lithium niobate single crystals of 200 and 300 μm thickness, respectively. We show that the domain diameter can be controlled with an uncertainty of a few percent. As-grown DWs are then subjected to a standard procedure of current-limited high-voltage DWC enhancement, and they repetitively reach a DWC increase of six orders of magnitude. While all resulting DWs show significantly enhanced DWC values, their individual current–voltage (I–V) characteristics exhibit different shapes, which can be explained by variations in their 3D real structure reflecting local heterogeneities by defects, DW pinning, and surface-near DW inclination.}},
  author       = {{Ratzenberger, Julius and Kiseleva, Iuliia and Koppitz, Boris and Beyreuther, Elke and Zahn, Manuel and Gössel, Joshua and Hegarty, Peter A. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  number       = {{10}},
  pages        = {{104302}},
  publisher    = {{AIP Publishing}},
  title        = {{{Toward the reproducible fabrication of conductive ferroelectric domain walls into lithium niobate bulk single crystals}}},
  doi          = {{10.1063/5.0219300}},
  volume       = {{136}},
  year         = {{2024}},
}

@article{59274,
  abstract     = {{Recently, ion exchange (IE) has been used to periodically modify the coercive field (Ec) of the crystal prior to periodic poling, to fabricate fine-pitch domain structures in Rb-doped KTiOPO4 (RKTP). Here, we use micro-Raman spectroscopy to understand the impact of IE on the vibrational modes related to the Rb/K lattice sites, TiO octahedra, and PO4 tetrahedra, which all form the basis of the RKTP crystal structure. We analyze the Raman spectra of three different RKTP samples: (1) a RKTP sample that shows a poled domain grating only, (2) a RKTP sample that has an Ec grating only, and (3) a RKTP sample that has both an Ec and a domain grating of the nominally same spacing. This allows us to determine the impact of IE on the vibrational modes of RKTP. We characterize the changes in the lower Raman peaks related to the alkali-metal ions, as well as observe lattice modifications induced by the incorporation of Rb+ that extend further into the crystal bulk than the expected IE depth. Moreover, the influence of IE on the domain walls is also manifested in their Raman peak shift. We discuss our results in terms of the deformation of the PO4and TiO groups. Our results highlight the intricate impact of IE on the crystal structure and how it facilitates periodic poling, paving the way for further development of the Ec-engineering technique.}},
  author       = {{Lee, Cherrie S. J. and Canalias, Carlota and Buschbeck, Robin and Koppitz, Boris and Hempel, Franz and Amber, Zeeshan and Eng, Lukas M. and Rüsing, Michael}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{21}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Impact of ion exchange on vibrational modes in Rb-doped KTiOPO4: A Raman spectroscopy study on the interplay between ion exchange and polarization switching}}},
  doi          = {{10.1103/physrevb.110.214115}},
  volume       = {{110}},
  year         = {{2024}},
}

@article{59275,
  abstract     = {{Studying and understanding many‐body interactions, particularly electron‐boson interactions, is essential for a deeper elucidation of fundamental physical phenomena and the development of novel material functionalities. Here, this aspect is explored in the weak itinerant ferromagnet LaCo2P2 by means of momentum‐resolved photoelectron spectroscopy (ARPES) and first‐principles calculations. The detailed ARPES patterns enable to unveil bulk and surface bands, spin splittings due to Rashba and exchange interactions, as well as the evolution of bands with temperature, which altogether creates a solid foundation for theoretical studies. The latter has allowed to establish the impact of electron‐boson interactions on the electronic structure, that are reflected in its strong renormalization driven by electron‐magnon interaction and the emergence of distinctive kinks of surface and bulk electron bands due to significant electron‐phonon coupling. Our results highlight the distinct impact of electron‐boson interactions on the electronic structure, particularly on the itinerant d states. Similar electronic states are observed in the isostructural iron pnictides, where electron‐boson interactions play a crucial role in the emergence of superconductivity. It is believed that further studies of material systems involving both magnetically active d‐ and f‐sublattices will reveal more advanced phenomena in the bulk and at distinct surfaces, driven by a combination of factors including Rashba and Kondo effects, exchange magnetism, and electron‐boson interactions.}},
  author       = {{Usachov, D. Yu. and Ali, K. and Poelchen, G. and Mende, M. and Schulz, S. and Peters, M. and Bokai, K. and Sklyadneva, I. Yu. and Stolyarov, V. and Chulkov, E. V. and Kliemt, K. and Paischer, S. and Buczek, P. A. and Heid, R. and Hempel, F. and Rüsing, Michael and Ernst, A. and Krellner, C. and Eremeev, S. V. and Vyalikh, D. V.}},
  issn         = {{2751-1200}},
  journal      = {{Advanced Physics Research}},
  publisher    = {{Wiley}},
  title        = {{{Unveiling Electron‐Phonon and Electron‐Magnon Interactions in the Weak Itinerant Ferromagnet LaCo2P2}}},
  doi          = {{10.1002/apxr.202400137}},
  year         = {{2024}},
}

@article{54967,
  abstract     = {{<jats:p>Ferroelectric domain wall conductivity (DWC) is an intriguing and promising functional property that can be elegantly controlled and steered through a variety of external stimuli such as electric and mechanical fields. Optical-field control, as a noninvasive and flexible tool, has rarely been applied so far, but it significantly expands the possibility for both tuning and probing DWC. On the one hand, as known from second-harmonic or Raman micro-spectroscopy, the optical approach provides information on DW distribution and inclination, while simultaneously probing the DW vibrational modes; on the other hand, photons might be applied to directly generate charge carriers, thereby acting as a functional and spectrally tunable probe to deduce the local absorption properties and bandgaps of conductive DWs. Here, we report on investigating the photo-induced DWC (PI-DWC) of three lithium niobate crystals, containing a very different number of DWs, namely: (A) none, (B) one, and (C) many conductive DWs. All three samples are inspected for their current–voltage behavior in darkness and for different illumination wavelengths swept from 500 nm down to 310 nm. All samples show their maximum PI-DWC at 310 nm; moreover, sample (C) reaches PI-DWCs of several microampere. Interestingly, a noticeable PI-DWC is also observed for sub-bandgap illumination, hinting toward the existence and decisive role of electronic in-gap states that contribute to the electronic charge transport along DWs. Finally, complementary conductive atomic force microscopy investigations under illumination proved that the PI-DWC indeed is confined to the DW area and does not originate from photo-induced bulk conductivity.</jats:p>}},
  author       = {{Ding, L. L. and Beyreuther, E. and Koppitz, B. and Kempf, K. and Ren, J. H. and Chen, W. J. and Rüsing, Michael and Zheng, Y. and Eng, L. M.}},
  issn         = {{0003-6951}},
  journal      = {{Applied Physics Letters}},
  number       = {{25}},
  publisher    = {{AIP Publishing}},
  title        = {{{Comparative study of photo-induced electronic transport along ferroelectric domain walls in lithium niobate single crystals}}},
  doi          = {{10.1063/5.0205877}},
  volume       = {{124}},
  year         = {{2024}},
}

@article{54966,
  abstract     = {{Piezoresponse force microscopy (PFM) is one of the most widespread methods for investigating and visualizing ferroelectric domain structures down to the nanometer length scale. PFM makes use of the direct coupling of the piezoelectric response to the crystal lattice, and hence, it is most often applied to spatially map the three-dimensional (3D) near-surface domain distribution of any polar or ferroic sample. Nonetheless, since most samples investigated by PFM are at least semiconducting or fully insulating, the electric ac field emerging from the conductive scanning force microscopy (SFM) tip penetrates the sample and, hence, may also couple to polar features that are deeply buried into the bulk of the sample under investigation. Thus, in the work presented here, we experimentally and theoretically explore the contrast and depth resolution capabilities of PFM, by analyzing the dependence of several key parameters. These key parameters include the depth of the buried feature, i.e., here a domain wall (DW), as well as PFM-relevant technical parameters such as the tip radius, the PFM drive voltage and frequency, and the signal-to-noise ratio. The theoretical predictions are experimentally verified using x-cut periodically poled lithium niobate single crystals that are specially prepared into wedge-shaped samples, in order to allow the buried feature, here the DW, to be “positioned” at any depth into the bulk. This inspection essentially contributes to the fundamental understanding in PFM contrast analysis and to the reconstruction of 3D domain structures down to a 1 μm-penetration depth into the sample.}},
  author       = {{Roeper, Matthias and Seddon, Samuel D. and Amber, Zeeshan H. and Rüsing, Michael and Eng, Lukas M.}},
  issn         = {{0021-8979}},
  journal      = {{Journal of Applied Physics}},
  keywords     = {{Ferroelectrics, lithium niobate, piezoresponse force microscopy}},
  number       = {{22}},
  publisher    = {{AIP Publishing}},
  title        = {{{Depth resolution in piezoresponse force microscopy}}},
  doi          = {{10.1063/5.0206784}},
  volume       = {{135}},
  year         = {{2024}},
}

@inproceedings{54303,
  author       = {{Böer, Nils Tobias and Güldenpenning, Iris and Weigelt, Matthias}},
  booktitle    = {{56. Jahrestagung der Arbeitsgemeinschaft für Sportpsychologie (ASP)}},
  editor       = {{Koester, Dirk and Krämer, Lina and Fuhlert, Leonhard and Everding, Jannik and Weilharter, Fritz and Marlovits, Andreas}},
  location     = {{Berlin}},
  pages        = {{119}},
  title        = {{{The influence of effort instruction on fake production costs in basketball novices and experienced basketball players.}}},
  year         = {{2024}},
}

@misc{59259,
  author       = {{Schwabe, Tobias and Rüsing, Michael and Staal, Niels and Schwengelbeck, Max and Bollmers, Laura and Padberg, Laura and Eigner, Christof and Silberhorn, Christine and Scheytt, J. Christoph}},
  publisher    = {{Zenodo}},
  title        = {{{Quantum photonic systems in CMOS compatible silicon nitride technology }}},
  doi          = {{10.5281/zenodo.15124929}},
  year         = {{2024}},
}

@article{60300,
  abstract     = {{This study focuses on the phenomenological change in material strength caused by a specific heat treatment and the subsequent analysis of the influence on the clinching process and the resulting joint properties. For this purpose, three series of tests were performed. In the first series of tests, the influence of heat treatment up to 340 °C on the mechanical properties of an age-hardenable AlMgSi alloy was investigated. Holding time and temperature were varied and the material strength was evaluated by tensile and hardness tests. Two strength-increasing and two strength-reducing heat treatment parameters were identified. In the second series of tests, selected heat treatment parameters were applied to a larger number of specimens and the joint strength was investigated by shear and head tensile tests. In the shear tensile test, mainly the properties of the punch-side material have an influence on the resulting joint strength. A change in strength of the die-side material can be neglected. In contrast, the properties of both sheets are important in the head tensile test. The strength of the joint will only increase if the strength of both sheets is increased. In general, a strength increasing heat treatment resulted in higher joint strength. In the third series of tests, the factor of punch displacement was considered, which was demonstrated to directly influence the formation of the clinched joint geometry.}},
  author       = {{Steinfelder, Christian and Rempel, Dennis and Brosius, Alexander}},
  issn         = {{2666-3309}},
  journal      = {{Journal of Advanced Joining Processes}},
  keywords     = {{Joining by forming, Clinching, EN AW-6014, Heat treatment, Load-bearing capacity}},
  publisher    = {{Elsevier BV}},
  title        = {{{Influence of the material properties on the clinching process and the resulting load-bearing capacity of the joint}}},
  doi          = {{10.1016/j.jajp.2024.100263}},
  volume       = {{10}},
  year         = {{2024}},
}

@article{60189,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Several state‐of‐the‐art algorithms for semi‐structured hexahedral meshing involve a so called <jats:italic>quantization</jats:italic> step to decide on the integer DoFs of the meshing problem, corresponding to the number of hexahedral elements to embed into certain regions of the domain. Existing reliable methods for quantization are based on solving a sequence of <jats:italic>integer quadratic programs</jats:italic> (IQP). Solving these in a timely and predictable manner with general‐purpose solvers is a challenge, even more so in the open‐source field. We present here an alternative robust and efficient quantization scheme that is instead based on solving a series of continuous <jats:italic>linear programs</jats:italic> (LP), for which solver availability and efficiency are not an issue. In our formulation, such LPs are used to determine where inflation or deflation of virtual hexahedral sheets are favorable. We compare our method to two implementations of the former IQP formulation (using a commercial and an open‐source MIP solver, respectively), finding that (a) the solutions found by our method are near‐optimal or optimal in most cases, (b) these solutions are found within a much more predictable time frame, and (c) the state of the art run time is outperformed, in the case of using the open‐source solver by orders of magnitude.</jats:p>}},
  author       = {{Brückler, Hendrik and Bommes, David and Campen, Marcel}},
  issn         = {{0167-7055}},
  journal      = {{Comput. Graph. Forum}},
  number       = {{5}},
  publisher    = {{Wiley}},
  title        = {{{Integer‐Sheet‐Pump Quantization for Hexahedral Meshing}}},
  doi          = {{10.1111/cgf.15131}},
  volume       = {{43}},
  year         = {{2024}},
}

@article{60240,
  author       = {{Ludwig, Ingmar and Campen, Marcel}},
  journal      = {{Comput. Graph. Forum}},
  number       = {{7}},
  pages        = {{i–xxii}},
  title        = {{{Strictly Conservative Neural Implicits}}},
  doi          = {{10.1111/CGF.15241}},
  volume       = {{43}},
  year         = {{2024}},
}

@inbook{32418,
  author       = {{Tönsing, Johanna}},
  booktitle    = {{Handbuch Deutsch-Türkischer Film}},
  editor       = {{Schulte-Eickholt, Swen and Bazarkaya, Onur}},
  title        = {{{Über „Gleis 11“ [Dokumentarfilm von 2021]}}},
  year         = {{2024}},
}

@inbook{53847,
  author       = {{Bartlitz, David}},
  booktitle    = {{Rechtstatsachen im Privatrecht}},
  editor       = {{Bartlitz, David and Eckert, Florian and Kurz, Franziska and Lang, David and Meichelbeck, Paulina and Meier, Dominik and Neubert, Konstantin and Odrig, Josephine}},
  isbn         = {{978-3-7560-0786-8}},
  pages        = {{9--36}},
  publisher    = {{Nomos Verlag}},
  title        = {{{Die Leiden des jungen (Datenaus-) Werthers - Einblicke in die Praxis der empirischen Rechtsforschung}}},
  doi          = {{10.5771/9783748915430}},
  year         = {{2024}},
}

@book{53845,
  editor       = {{Bartlitz, David and Eckert, Florian and Kurz, Franziska and Lang, David and Meichelbeck, Paulina and Meier, Dominik and Neubert, Konstantin and Odrig, Josephine}},
  isbn         = {{978-3-7560-0786-8}},
  pages        = {{295}},
  publisher    = {{Nomos Verlag}},
  title        = {{{Rechtstatsachen im Privatrecht}}},
  doi          = {{10.5771/9783748915430}},
  year         = {{2024}},
}

@book{54190,
  editor       = {{Bartlitz, David and Klunzinger, Eugen and Hoffmann, Jochen}},
  isbn         = {{978-3-8006-7453-4}},
  pages        = {{780}},
  publisher    = {{Franz Vahlen}},
  title        = {{{Einführung in das Bürgerliche Recht}}},
  doi          = {{10.15358/9783800674541}},
  year         = {{2024}},
}

@article{60413,
  author       = {{Bartlitz, David}},
  journal      = {{Zeitschrift für Wirtschaftsrecht (ZIP)}},
  number       = {{12}},
  pages        = {{616--617}},
  title        = {{{Keine negativen Zinsen bei Berechnung der Vorfälligkeitsentschädigung. Anmerkung zu OLG Nürnberg, Urt. v. 25. 7. 2023 - 14 U 2764/22}}},
  year         = {{2024}},
}

@inbook{56177,
  author       = {{Knoll, Lisa}},
  booktitle    = {{The Routledge International Handbook of Valuation and Society}},
  editor       = {{Krüger, Anne and Peetz, Thorsten and Schaefer, Hilmar}},
  pages        = {{316--325}},
  publisher    = {{Routledge}},
  title        = {{{Valuation and Sustainability}}},
  year         = {{2024}},
}