A5030641347- Muon and positron interactions and applications
- Copper Interconnects and Reliability
- Metal-Organic Frameworks: Synthesis and Applications
- Semiconductor materials and devices
- Membrane Separation and Gas Transport
- ZnO doping and properties
- Ammonia Synthesis and Nitrogen Reduction
- Crystallization and Solubility Studies
- Ion-surface interactions and analysis
- X-ray Diffraction in Crystallography
- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Graphene research and applications
- Advanced Condensed Matter Physics
- Microstructure and mechanical properties
- Nuclear Physics and Applications
- Advanced ceramic materials synthesis
- Multiferroics and related materials
- Chemical Synthesis and Characterization
- Synthesis and characterization of novel inorganic/organometallic compounds
- Plasma Diagnostics and Applications
- Silicone and Siloxane Chemistry
- Aluminum Alloy Microstructure Properties
- Lanthanide and Transition Metal Complexes
- Copper-based nanomaterials and applications
Helmholtz-Zentrum Dresden-Rossendorf
2019-2025
Minia University
2012-2025
Institute of Radiation Physics
2024
Martin Luther University Halle-Wittenberg
2016-2020
Francke Foundations
2017
Carbon dioxide (CO2) is a major greenhouse gas contributing to global warming. Adsorption in porous sorbents offers promising method mitigate CO2 emissions by capturing and storage. The zinc-triazole-oxalate-based metal-organic framework CALF-20 demonstrates high capacity, low H2O affinity, adsorption heat, enhancing energy efficiency while maintaining stable performance over multiple adsorption/desorption cycles. This study examines CALF-20. Using the combination of positron annihilation...
Abstract Carbon dioxide (CO 2 ) is a major greenhouse gas contributing to global warming. Adsorption in porous sorbents offers promising method for CO capture and storage. The zinc‐triazole‐oxalate‐based Calgary framework 20 (CALF‐20) demonstrates high capacity, low H O affinity, adsorption heat, enabling energy‐efficient stable performance over multiple cycles. This study examines mechanism CALF‐20 using positron annihilation lifetime spectroscopy (PALS), situ powder X‐ray diffraction...
A nanopore engineering approach enhances acetylene (C2H2) over carbon dioxide (CO2) selectivity in ionic ultramicroporous polymers (IUPs), an understudied class of sorbents. Extending the cationic arm a prototypical IUP nearly doubles its C2H2/CO2 from 4.9 to 8.5 (at 298 K, 1 bar), underpinned by further observations dynamic separation experiments and bespoke computational insights.
Abstract Magneto‐ionics relies on the voltage‐driven transport of ions to modify magnetic properties. As a diffusion‐controlled mechanism, defects play central role in determining ion motion and, hence, magneto‐ionic response. Here, potential implantation is exploited engineer depth‐resolved defect type and density with aim control behavior Co 3 O 4 thin films. It demonstrated that through single process light (He + ) at 5 keV, response nanostructured 50 nm thick film, terms rate amount...
Abstract The oxidation of chromium in air at 700 °C was investigated with a focus on point defect behavior and transport during oxide layer growth. A comprehensive set characterization techniques targeted characteristics microstructure chemical composition analysis. TEM showed that the thicker longer times that, for oxides, voids formed metal/oxide interface. PAS revealed time, there an overall reduction vacancy-type defects, though monovacancies were not found either case. EIS oxidized...
Abstract Thin films of the magnetoelectric insulator α ‐Cr 2 O 3 are technologically relevant for energy‐efficient magnetic memory devices controlled by electric fields. In contrast to single crystals, quality thin Cr is usually compromised presence point defects and their agglomerations at grain boundaries, putting into question application potential. Here, impact defect nanostructure, including sparse small‐volume complexes studied on properties films. By tuning deposition temperature,...
Metal-organic frameworks (MOFs) stand as pivotal porous materials with exceptional surface areas, adaptability, and versatility. Positron Annihilation Lifetime Spectroscopy (PALS) is an indispensable tool for characterizing MOF porosity, especially micro- mesopores in both open closed phases. Notably, PALS offers porosity insights independent of probe molecules, which vital detailed characterization without structural transformations. This study explores how metal ion states MOFs affect...
LiMn2O4 (LMO) cathodes present large stability when cycled in aqueous electrolytes, contrasting with their behavior conventional organic electrolytes lithium-ion batteries (LIBs). To elucidate the mechanisms underlying this distinctive behavior, we employ unconventional characterization techniques, including variable energy positron annihilation lifetime spectroscopy (VEPALS), tip-enhanced Raman (TERS), and macro-Raman (with tens of μm-size laser spot). These still rather unexplored...
Abstract An extended member of the isoreticular family metal–imidazolate framework structures, IFP‐6 (IFP=imidazolate Potsdam), based on cadmium metal and an in situ functionalized 2‐methylimidazolate‐4‐amide‐5‐imidate linker is reported. A porous 3D with 1D hexagonal channels accessible pore windows 0.52 nm has been synthesized by using ionic liquid (IL) precursor. shows significant gas uptake capacity only for CO 2 CH 4 at elevated pressure, whereas it does not adsorb N , H under...
The Helmholtz-Zentrum Dresden-Rossendorf operates a superconducting linear accelerator for electrons with energies up to 35 MeV and average beam currents 1.6 mA. electron is employed production of several secondary beams including X-rays from bremsstrahlung production, neutrons, positrons. positron after moderation feeds the Monoenergetic Positron Source (MePS) where annihilation lifetime (PALS) Doppler-broadening experiments in materials science are performed parallel. adjustable repetition...
Magneto-ionics refers to the control of magnetic properties materials through voltage-driven ion motion. To generate effective electric fields, either solid or liquid electrolytes are utilized, which also serve as reservoirs. Thin have difficulties in (i) withstanding high fields without pinholes and (ii) maintaining stable transport during long-term actuation. In turn, use can result poor cyclability, thus limiting their applicability. Here we propose a nanoscale-engineered magneto-ionic...
Atmospheric water harvesting with metal-organic frameworks (MOFs) is a new technology providing clean, long-term supply in arid areas. In-situ positron annihilation lifetime spectroscopy (PALS) proposed as valid methodology for the mechanistic understanding of sorption MOFs and selection prospective candidates desired applications. DUT-67-Zr DUT-67-Hf are used model systems method validation because their hierarchical pore structure, high adsorption capacity, chemical stability. Both...
DUT-8(Ni) metal-organic framework (MOF) belongs to the family of flexible pillared layer materials. The desolvated can be obtained in open pore form (op) or closed (cp), depending on crystal size regime. In present work, we report behaviour at elevated temperatures. For both, op and cp variants, heating causes a structural transition, leading new, crystalline compound, containing two interpenetrated networks. state before transition (op vs. cp) influences temperature: small particles phase...
Extending the potential window toward 3 V plateau below typically used range could boost effective capacity of LiMn2O4 spinel cathodes. This usually leads to an "overdischarge" cathode, which can cause severe material damage due manganese dissolution into electrolyte and a critical volume expansion (induced by Jahn–Teller distortions). As those factors determine stability cycling lifetime for all-solid-state batteries, operational is limited 3.5–4.5 versus Li/Li+ in common battery cells....
Microwave assisted synthesized materials have an inherent ability to trap extra linkers, thereby reducing the pore sizes of CE- heating ultra/micropores. These ultramicropores are responsible for high gas sorption.
Magnetoelectric antiferromagnets like Cr2O3 are attractive for the realization of energy-efficient and high-speed spin–orbitronic-based memory devices. Here, we demonstrate that fabrication polycrystalline bulk samples in conditions far out equilibrium relying on spark plasma sintering allows high-quality material with a density close to single crystal be realized. The sintered sample possesses preferential [0001] texture at surface, which can attributed uniaxial strain applied during...
In situ imidazolate-4,5-diamide-2-olate (L2) linker generation under conventional electrical (CE) heating and microwave (MW)-assisted conditions leads to the formation of porous three-dimensional hydrogen-bonded molecular building block (MBB) [Cd14(L2)12(O)(OH)2(H2O)4(DMF)4] based network, named as HIF-3. MBB a Cd6 octahedron is inscribed in Cd8 cube. The evacuated materials show good N2, CO2, H2 gas sorption, comparison with other H-bonded networks. desorption branches exhibit broad...
The gas–framework interaction induced gate-opening phenomenon occurring in zeolitic imidazolate frameworks (ZIFs) has restricted the ability of conventional experimental techniques involving gas or liquid molecules intrusion ZIFs for determination their inherent pore structure. structure investigation ZIF-based membranes/thin films using becomes even more difficult due to limited amount material, and existence pores that are not connected exterior surface. membranes proposed as an advanced...
We present a newly developed instrument for 22Na-based positron-annihilation lifetime spectroscopy, designed to facilitate the simultaneous control of temperature, gas atmosphere, and humidity in single experimental system. The spectrometer operates within temperature range 50–480 K pressures from 10−6 mbar 1.5 bars. It features novel dosing chamber that allows situ adsorption studies with gases such as but not limited CO2, N2, Ar, O2, their mixtures, precise over mixing ratios....
Abstract The microporosity, structure and permeability of SiO x thin films deposited by microwave plasma‐enhanced chemical vapour deposition (PE‐CVD) atomic layer (PE‐ALD) on polydimethylsiloxane (PDMS) substrates were investigated positron annihilation spectroscopy complementary technique, such as X‐ray photoelectron spectroscopy, infrared time flight mass force microscopy. onto spin‐coated PDMS substrates, which previously exposed to an oxygen plasma thus achieving the conversion top...