A5101740602- Geophysics and Gravity Measurements
- Magnetic and transport properties of perovskites and related materials
- GNSS positioning and interference
- Advanced Condensed Matter Physics
- Advancements in Battery Materials
- Inertial Sensor and Navigation
- Iron-based superconductors research
- Geomagnetism and Paleomagnetism Studies
- Physics of Superconductivity and Magnetism
- Molecular Junctions and Nanostructures
- Rare-earth and actinide compounds
- Ionosphere and magnetosphere dynamics
- Advanced Battery Materials and Technologies
- Solar and Space Plasma Dynamics
- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- Fullerene Chemistry and Applications
- Magnetic properties of thin films
- Porphyrin and Phthalocyanine Chemistry
- Extraction and Separation Processes
- Graphene research and applications
- Force Microscopy Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Organic Electronics and Photovoltaics
- Inorganic Chemistry and Materials
Karlsruhe Institute of Technology
2015-2025
The University of Texas at Austin
2002-2024
Fraunhofer Institute for Integrated Circuits
2012
FZI Research Center for Information Technology
1998-2011
University of Tübingen
2008
Heidelberg University
2002-2004
FIZ Karlsruhe – Leibniz Institute for Information Infrastructure
2004
Leibniz University Hannover
1978
Abstract Since June, 2018, the Gravity Recovery and Climate Experiment Follow‐On (GRACE‐FO) is extending 15‐year monthly mass change record of GRACE mission, which ended in June 2017. The GRACE‐FO instrument flight system performance has improved over GRACE. Better attitude solutions enhanced pointing result reduced fuel consumption gravity range rate post‐fit residuals. One accelerometer requires additional calibrations due to unexpected measurement noise. fields from 2018 through December...
$\mathrm{La}\mathrm{Co}{\mathrm{O}}_{3}$ films grown epitaxially on ⟨001⟩ oriented ${(\mathrm{La}\mathrm{Al}{\mathrm{O}}_{3})}_{0.3}{({\mathrm{Sr}}_{2}\mathrm{Al}\mathrm{Ta}{\mathrm{O}}_{6})}_{0.7}$ substrates by pulsed laser deposition exhibit ferromagnetic ordering below a critical temperature, ${T}_{c}$, of $85\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Polycrystalline prepared in the same way did not show order down to $T\ensuremath{\approx}5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, and their...
Molecular patterning processes taking place in biological systems are challenging to study vivo because of their dynamic behavior, subcellular size, and high degree complexity. In vitro biomolecules using nanolithography allows simplification the detailed interactions. Parallel dip-pen (DPN) is uniquely capable integrating functional on length scales due its constructive nature, resolution, throughput. Phospholipids particularly well suited as inks for DPN since a variety different lipids...
Epitaxial thin films of undoped LaCoO$_{3}$\@, electron-doped La$_{0.7}$Ce$_{0.3}$CoO$_{3}$\@, and hole-doped La$_{0.7}$Sr$_{0.3}$CoO$_{3}$\@ exhibit ferromagnetic order with a transition temperature $T_{\rm{C}}$ $\approx$ 85 K, 22 240 respectively. The spin-state structure for these compounds was studied by soft x-ray magnetic circular dichroism at the Co $L_{2,3}$ O $K$ edges. It turns out that higher spin state Co$^{3+}$ ions is responsible magnetism in LaCoO$_{3}$\@ while...
Using neutron reflectometry and resonant x-ray techniques we studied the magnetic proximity effect (MPE) in superlattices composed of superconducting YBa2Cu3O7 ferromagnetic-metallic La0.67Ca0.33MnO3 or ferromagnetic-insulating LaMnO(3+δ). We find that MPE strongly depends on electronic state manganite layers, being pronounced for almost absent also detail change depth profile due to provide evidence its intrinsic nature.
The degradation of LiNi0.8Co0.15Al0.05O2 (LNCAO) is reflected by the electrochemical performance in fatigued state and correlated with redox behavior these cathodes. detailed samples investigated galvanostatic voltammetric cycling as well intermittent titration technique (GITT). Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was used to investigate oxidation all three materials at Ni L2,3, O K, Co L2,3 edges five different states charge. Surface more bulklike properties are...
The syntheses of Ni-poor (NCM111, LiNi1/3Co1/3Mn1/3O2) and Ni-rich (NCM811 LiNi0.8Co0.1Mn0.1O2) lithium transition-metal oxides (space group R3̅m) from hydroxide precursors (Ni1/3Co1/3Mn1/3(OH)2, Ni0.8Co0.1Mn0.1(OH)2) are investigated using in situ synchrotron powder diffraction near-edge X-ray absorption fine structure spectroscopy. development the layered these two cathode materials proceeds via utterly different reaction mechanisms. While synthesis NCM811 involves a rock salt-type...
Abstract The high-voltage oxygen redox activity of Li-rich layered oxides enables additional capacity beyond conventional transition metal (TM) contributions and drives the development positive electrode active materials in secondary Li-based batteries. However, often face voltage decay during battery operation. In particular, although with a high nickel content demonstrate improved stability, they suffer from poor discharge capacity. Here, via physicochemical electrochemical measurements,...
In this study, we present a comparison of coincident GRACE and ICESat data over Antarctica. The analysis focused on the secular changes 4-year period spanning from 2003 to 2007, using recently reprocessed publicly available sets for both missions. results show that two independent possess strong spatial correlations, but there are several factors can significantly impact total derived ice mass variability For GRACE, primary source uncertainty comes modelling glacial isostatic adjustment,...
The Li–Ni–O phase diagram contains a variety of compounds, most which are electrochemically active in Li-ion batteries. Other than the well-known LiNiO2, here we report facile solid-state method to prepare Li2NiO3 and other Li-rich Ni oxides composition Li1+xNi1–xO2 (0 ≤ x 0.33). We characterize their crystal electronic structure, exhibiting highly oxidized state defects various nature (Li–Ni disorder, stacking faults, oxygen vacancies). then investigate use as cathode material show its...
Abstract The Gravity Recovery and Climate Experiment Follow‐On (GRACE‐FO), launched May 22, 2018 collecting science data since June 2018, is extending the 15‐year record of Earth mass change established by its predecessor GRACE mission (2002–2017). GRACE‐FO satellites carry onboard a novel technology demonstration instrument for intersatellite ranging, Laser Ranging Interferometer (LRI), in addition to microwave interferometer (MWI) carried on GRACE. LRI has out‐performed in‐orbit...
Bond formation and breakage is crucial upon energy storage in lithium transition metal oxides (Li Me O 2 , = Ni, Co, Mn), i.e. the conventional cathode materials Li ion batteries. Near-edge X-ray absorption finestructure spectroscopy (NEXAFS) of L K edge performed first discharge LiNi x Co (1−x)/2 Mn ( 0.33: NCM111, 0.6: NCM622, 0.8: NCM811) combination with charge transfer multiplet (CTM) calculations provide unambiguous evidence that redox reactions NCMs proceed via a reversible oxidation...
Abstract Direct recycling is a key technology for enabling circular economy of spent lithium ion batteries (LIBs). For cathode active materials (CAMs), it regarded as the tightest closed‐loop and most efficient approach among current techniques simply proceeds via re‐lithiation reconstruction aged CAMs instead separating them into elemental components. In this work, spent, i.e., morphologically structurally decomposed CAM based on LiNi 0.83 Co 0.12 Mn 0.05 O 2 (NCM‐831205) restored by...
Abstract Rechargeable lithium‐ion batteries (LIBs) are critical for enabling sustainable energy storage. The capacity of cathode materials is a major limiting factor in the LIB performance, and doping has emerged as an effective strategy enhancing electrochemical properties nickel‐rich layered oxides such NCM811. In this study, boron homogeneously incorporated into tetrahedral site NCM811 through co‐precipitation, leading to inductive effect on transition metal ( TM )‐O‐B bonds that delayed...
The Sentinel-6A satellite, launched on November 21, 2020, is equipped with a dual-constellation (Galileo and GPS) onboard receiver for precise orbit determination (POD). Since launch, there have been significant improvements in the force models data processing strategies. This has resulted to accuracy. Gravity Recovery Climate Experiment-Continuity (GRACE-C) mission, which will be 2028, carry similar Sentinel-6A. main purposes of this study are extend our software process both Galileo GPS...
The thermodynamics of the superconducting transition is studied as a function doping using high-resolution expansivity data YBa(2)Cu(3)O (x) single crystals and Monte Carlo simulations anisotropic 3D- XY model. We directly show that T(c) underdoped strongly suppressed from its mean-field value (T(MF)(c)) by phase fluctuations order parameter. For overdoped fluctuation effects are greatly reduced approximately T(MF)(c). find T(MF)(c) exhibits similar dependence pseudogap energy, naturally...
Synergistic synchrotron x-ray absorption experiments using imaging magnetic microspectroscopy, circular dichroism, and ab initio calculations on FeCr alloys reveal that the Cr content strongly influences ferromagnetic microstructure Fe moments. The local structure resolved by extended fine (EXAFS) is also found to be affected alloy's composition. Both EXAFS show a change in atomic above 10 at.% from distance contraction of first two coordination shells around absorbing atom. These results...
The doping-dependent valence, orbital, and spin-state configurations of single-layered La${}_{2\ensuremath{-}x}$Ca${}_{x}$CoO${}_{4}$ ($x=0$, 0.5, 1, 1.5) were investigated with temperature-dependent near-edge x-ray absorption fine structure at the Co ${L}_{2,3}$ O $K$ edges. spectra show that in La${}_{2}$CoO${}_{4}$, superexchange between neighboring Co${}^{2+}$ HS states is responsible for strong antiferromagnetism. With increasing hole doping, interactions ions are rapidly reduced by...
Iron- and manganese-based layered electrodes for sodium-ion batteries have attracted renewed interest due to their low cost environmental friendliness. However, phase changes at high voltage the Jahn–Teller effect lead a short cycle life poor rate capability. Herein, we describe optimization of structure Co/Ni free Na2/3Mn1/2Fe1/2O2 cathode via partial substitution Fe by Mn Ti explore redox activity P2-type Mn/Fe-based cathodes. The obtained P2–Na2/3Mn7/12Fe1/3Ti1/12O2 (NMFTO) exhibits solid...
The growth of copper phthalocyanine thin films evaporated on polycrystalline gold is examined in detail using near edge x-ray absorption fine structure spectroscopy and surface sensitive photoemission spectroscopy. combination both methods allows distinguishing between the uppermost layers buried interface up to approximately 3 nm thickness. An interfacial layer ML molecules with an orientation parallel substrate was found, whereas subsequent are perpendicular metal surface. It shown that...
Epitaxial thin films of LaCoO_{3} (E-LCO) exhibit ferromagnetic order with a transition temperature T_c = 85 K, while polycrystalline (P-LCO) remain paramagnetic. The temperature-dependent spin-state structure for both E-LCO and P-LCO was studied by x-ray absorption spectroscopy at the Co L_{2,3} O K edges. Considerable spectral redistributions over are observed P-LCO. spectra E-LCO, on other hand, do not show any significant changes temperatures between 30 450 edges, indicating that spin...