Research Data Repository of Saxon Universities
OPARA is the Open Access Repository and Archive for Research Data of Saxon Universities.
Researchers of Saxon Universities can either publish their research data on OPARA, or archive it here to comply with requirements of funding acencies and good scientic practice, without public access.
You can find the documentation of this service at the ZIH Data Compendium websites. If you need suppourt using OPARA please contact the Servicedesk of TU Dresden.
Please note: The OPARA service was recently upgraded to a new technical platform (this site). Previously stored data will not be available here immediately. It can be found at the still active old version of OPARA. These stock data will be migrated in near future and then the old version of OPARA will finally be shut down. Existing DOIs for data publications remain valid.
Communities in OPARA
Select a community to browse its collections.
Recent Submissions
BaFe11TiO19 Vortex EMCD
(Technische Universität Dresden, 2026-01-08) Pohl, Darius; Makino, Hitoshi; Ernst, Arthur; Negi, Devendra; Schneider, Sebastian; Erni, Rolf; Rusz, Jan
We demonstrate atomic-scale mapping of local magnetic moments and doping effects in Ti-doped barium hexaferrite (BaFe11TiO19) using atom-sized electron vortex beams (EVBs) with controlled orbital angular momentum (OAM) in a scanning transmission electron microscope. By measuring electron energy loss magnetic circular dichroism (EMCD) at the Fe − L2,3 edges, we directly resolve the spatial distribution of antiparallel-aligned magnetic sublattices and quantify the impact of non-magnetic Ti4+ substitution. The EMCD signal, detected from single atomic Fe columns, reveals a marked reduction and sign reversal in the magnetic moment at Ti-rich 4f2 sites, corroborated by inelastic scattering simulations and density functional theory calculations that indicate induced Fe2+ formation and modified exchange interactions. Our results show that EVBs enable direct, element-specific, and atomically resolved magnetic characterization, opening new avenues for investigating local magnetic phenomena and dopant effects in nano-structured magnetic materials, such as those used in spintronic devices. This method paves the way for detailed studies of complex spin textures, magnetic interfaces, and dynamic processes at the atomic scale.
Dataset includes raw data, DFT simulation of the DOS (BaFe12O19, BaFe11TiO19) and inelastic scattering simulation data.
Controlling structural instability in the Cu$_{12-x}$Ni$_x$Sb$_4$S$_{13}$ ($x$\,=\,0, 0.05, 0.2, 0.5) tetrahedrites
(Technische Universität Bergakademie Freiberg, 2026-01-08) Bolielyi, Oleksandr; Dobrozhan, Oleksandr; Levytskyi, Volodymyr; Tsirlin, Alexander A.; Pshenychnyi, Roman; Leithe-Jasper, Andreas; Gumeniuk, Roman
Cu$_{12-x}$Ni$_x$Sb$_4$S$_{13}$ ($x\,=\,0, 0.05, 0.2, 0.5$) tetrahedrites were synthesized by the polyol method. Measurements of magnetic susceptibility, specific heat capacity as well as electrical and thermal transport properties indicated a structural phase transition (SPT) of 1$^{\mathrm{st}}$ order at $T_k\,=\,75-85$\,K, which is accompanied by strong changes in electronic density of states (EDOS) and entropy for $x\,=\,0, 0.05, 0.2$ whereas only weak changes were observed at $x\,=\,0.5$. However, further temperature dependent synchrotron high-resolution powder X-ray diffraction (HR PXRD) studies indicated compounds with Ni-content $x\,=\,0$ and 0.5 to remain body-centered cubic [space group (SG) $I\bar{4}3m$, $a\,\approx\,10.4(1)$\,\AA] down to 10\,K, whereas crystal structures of $x\,=\,0, 0.05$ and 0.2 became tetragonal, (SG $P\bar{4}c2$, $a_\mathrm{tetr}\,\approx\,a_\mathrm{cub}\sqrt{2}$, $c_\mathrm{tetr}\,\approx\,a_\mathrm{cub}$) below $T_k$. Comparing changes of EDOS at the Fermi level [$\Delta N^{(E_\mathrm{F})}$] deduced from magnetic and thermodynamic data with those calculated from density functional theory (DFT) assuming the validity of the rigid-band approximation, we found $\Delta N^{(E_\mathrm{F})}_\mathrm{theor}\,\approx\,0$ when compared with cubic and tetragonal arragements for Cu$_{11.5x}$Ni$_{0.5}$Sb$_4$S$_{13}$, which indicate the latter to be unstable. This study shows that SPT in tetrahedites is facilitated by the presence of minor amount of a dopant.
Fine root vitality decline results in reduced branch formation in mature beech stands after drought - Dataset
(Technische Universität Dresden, 2026-01-06) Koller, Alexandra Vivian
Climate change is deteriorating the health, growth and thus functioning and services of forests through i.a. ongoing droughts, heatwaves and altered precipitation patterns, and an increase in the severity of these effects is predicted. Although fine roots can serve as an early indicator of drought stress, we still lack an understanding of how tree fine root vitality is reflected in aboveground tree morphology. Our study uses multitemporal fine root data obtained by sequential coring, as well as high-resolution tree crown data obtained by terrestrial laser scanning in mature European beech (Fagus sylvatica) stands. First, we assessed which fine root vitality traits are affected by drought, and second, evaluated the relationship between fine root vitality and crown vitality including trees within three different radial distances (5, 8 or 10 m) from the fine root sampling point. We found that fine root necromass, fine root biomass to necromass ratio and turnover were correlated with drought. Mainly fine roots in the upper 10 cm of soil affected the crown vitality of beech trees within a 5-m radius of the fine root sampling point, highlighting the tree-centred horizontal distribution of fine roots and shallow rooting pattern of beech. A decreased fine root vitality in the upper soil in the previous growing seasons led to decreased crown vitality. Including fine root inventories in forest monitoring protocols could substantially improve our understanding of the status and trends of forests and enable forest management to deal more effectively with the growing pressure on forests.
LASANA: Laparoscopic Skill Analysis and Assessment video dataset
(Technische Universität Dresden, 2025-12-26) Funke, Isabel; Bodenstedt, Sebastian; von Bechtolsheim, Felix; Oehme, Florian; Maruschke, Michael; Petzsch, Stefanie; Weitz, Jürgen; Distler, Marius; Mees, Sören Torge; Speidel, Stefanie
The LASANA video dataset comprises 1270 trimmed and synchronized stereo video recordings of four basic laparoscopic training tasks (peg transfer, circle cutting, balloon resection, and suture & knot). Per task, there are at least 311 recordings in the dataset.
Each recording is annotated with a structured skill rating, aggregated across three independent raters, as well as binary labels indicating the presence or absence of task-specific errors (for example, dropping an object during the peg transfer task, or puncturing the inner balloon during the balloon resection task).
The LASANA video dataset is intended to support the development and evaluation of methods for automatic video-based laparoscopic skill analysis. For benchmarking, a fixed datasplit into training, validation, and test videos is provided for each task.
Supplemetary information and dataset to the publication "Evaluation of the tensile adhesion strength of cathode coatings from spent lithium-ion batteries using a centrifugal method"
(Technische Universität Bergakademie Freiberg, 2025-12-22) Dahl, Konstantin; Löwer, Erik; Kaas, Alexandra; Peuker, Urs A.
Lithium-ion batteries are essential for the transition to renewable energy and electrified transport. As their use continues to grow, efficient and sustainable recycling processes are needed to recover valuable materials from spent battery cells. Such industrial recycling processes often rely on hydrometallurgical extraction of valuable metals and require selective removal of cathode coatings from metallic current collector foils beforehand. The efficiency of this decoating strongly affects the yield and purity of the recovered material fractions. In parallel, direct recycling concepts that aim to preserve the structure and functionality of cathode active materials for re-use depend even more critically on controlled decoating with minimal damage to the coating materials. In both cases, the adhesion between these coatings and their substrate foils is a key parameter that governs how easily active material layers can be detached and how efficient the resulting streams of active material and current collector foil can be separated. In this context, a centrifugal testing method was developed to quantify the tensile adhesion strength of cathode coatings and to assess fracture under defined processing conditions. The method enables a systematic evaluation of how different pre-treatment strategies, such as thermal drying, affect coating adhesion. Here it is applied to cathode foils from end-of-life NMC-111 cells thermally pre-treated in air at room temperature, 80 °C, 140 °C, 310 °C and 350 °C. Depending on the pre-treatment temperature, the fracture behavior shifts markedly between adhesive and cohesive modes.