A5076010766- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Inorganic Chemistry and Materials
- Boron and Carbon Nanomaterials Research
- Diamond and Carbon-based Materials Research
- Metal and Thin Film Mechanics
- Crystal Structures and Properties
- Geological and Geochemical Analysis
- MXene and MAX Phase Materials
- Crystallography and molecular interactions
- Inorganic Fluorides and Related Compounds
- Advanced Condensed Matter Physics
- Advanced Chemical Physics Studies
- Rare-earth and actinide compounds
- Organic and Molecular Conductors Research
- Electronic and Structural Properties of Oxides
- Catalysis and Oxidation Reactions
- Solid-state spectroscopy and crystallography
- Physics of Superconductivity and Magnetism
- Chemical Thermodynamics and Molecular Structure
- Iron oxide chemistry and applications
- Energetic Materials and Combustion
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced materials and composites
Goethe University Frankfurt
2023-2025
University of Cologne
2022-2025
Czech Academy of Sciences, Institute of Inorganic Chemistry
2023-2025
University of Bayreuth
2015-2024
Carnegie Institution for Science
2020-2023
Howard University
2020-2022
Earth and Planets Laboratory
2021
Deutsches Elektronen-Synchrotron DESY
2019-2021
Geophysical Laboratory
2020-2021
Bayer (Germany)
2015-2020
Abstract Although chemically very simple, Fe 2 O 3 is known to undergo a series of enigmatic structural, electronic and magnetic transformations at high pressures temperatures. So far, these have neither been correctly described nor understood because the lack structural data. Here we report systematic investigation behaviour over 100 GPa temperatures above 2,500 K employing single crystal X-ray diffraction synchrotron Mössbauer source spectroscopy. Crystal chemical analysis structures...
Terapascal static pressure generation is enabled in laboratory due to implementation of nanocrystralline diamond microballs.
Poly-nitrogen compounds have been considered as potential high energy density materials for a long time due to the large number of energetic N-N or N=N bonds. In most cases nitrogen content and stability at ambient conditions are mutually exclusive, thereby making synthesis such challenging. One way stabilize is application pressure. Here, through direct reaction between Fe N
The layered compound BeN${}_{4}$, berillontirene, is a Dirac semimetal with linear dispersion in the vicinity of Fermi energy and two points coinciding energy, similar to graphene.
The presence of carbonates in inclusions diamonds coming from depths exceeding 670 km are obvious evidence that exist the Earth's lower mantle. However, their range stability, crystal structures and thermodynamic conditions decarbonation processes remain poorly constrained. Here we investigate behaviour pure iron carbonate at pressures over 100 GPa temperatures 2,500 K using single-crystal X-ray diffraction Mössbauer spectroscopy laser-heated diamond anvil cells. On heating to geotherm ∼50...
Abstract The synthesis of polynitrogen compounds is fundamental importance due to their potential as environmentally-friendly high energy density materials. Attesting the intrinsic difficulties related formation, only three ions, bulk stabilized salts, are known. Here, magnesium and molecular nitrogen compressed about 50 GPa laser-heated, producing two chemically simple salts anions, MgN 4 Mg 2 N . Single-crystal X-ray diffraction reveals infinite anionic polythiazyl-like 1D N-N chains in...
Most of the studied two-dimensional (2D) materials are based on highly symmetric hexagonal structural motifs. In contrast, lower-symmetry structures may have exciting anisotropic properties leading to various applications in nanoelectronics. this work we report synthesis nickel diazenide NiN2 which possesses atomic-thick layers comprised Ni2N3 pentagons forming Cairo-type tessellation. The weakly bonded with calculated exfoliation energy 0.72 J/m2, is just slightly larger than that graphene....
Abstract Theoretical modelling predicts very unusual structures and properties of materials at extreme pressure temperature conditions 1,2 . Hitherto, their synthesis investigation above 200 gigapascals have been hindered both by the technical complexity ultrahigh-pressure experiments absence relevant in situ methods analysis. Here we report on a methodology developed to enable static compression terapascal regime with laser heating. We apply this method realize pressures about 600 900...
The yttrium-hydrogen system has gained attention because of near-ambient temperature superconductivity reports in yttrium hydrides at high pressures. We conducted a study using synchrotron single-crystal x-ray diffraction (SCXRD) 87 to 171 GPa, resulting the discovery known (two YH
Abstract A nitrogen‐rich compound, ReN 8 ⋅x N 2 , was synthesized by a direct reaction between rhenium and nitrogen at high pressure temperature in laser‐heated diamond anvil cell. Single‐crystal X‐ray diffraction revealed that the crystal structure, which is based on framework, has rectangular‐shaped channels accommodate molecules. Thus, despite very synthesis pressure, exceeding 100 GPa, an inclusion compound. The amount of trapped (x) depends conditions. polydiazenediyl chains [−N=N−] ∞...
Abstract The synthesis of polynitrogen compounds is great importance due to their potential as high‐energy‐density materials (HEDM), but because the intrinsic instability these compounds, and stabilization a fundamental challenge. Polymeric nitrogen units which may be stabilized in with metals at high pressure are now restricted non‐branched chains an average N−N bond order 1.25, limiting HEDM performances. Herein, we demonstrate novel compound TaN 5 via direct reaction between tantalum...
The chemical interaction of Sn with H2 by X-ray diffraction methods at pressures 180-210 GPa is studied. A previously unknown tetrahydride SnH4 a cubic structure (fcc) exhibiting superconducting properties below TC = 72 K obtained; the formation high molecular C2/m-SnH14 superhydride and several lower hydrides, fcc SnH2 , C2-Sn12 H18 also detected. temperature dependence critical current density JC (T) in yields gap 2Δ(0) 21.6 meV 180 GPa. has unusual behavior strong magnetic fields:...
Compression of dimethylammonium metal formates results in distorted formate frameworks and loss dynamic disorder simultaneously.
Abstract The combination of laser‐heated diamond anvil cells and synchrotron Mössbauer source spectroscopy were used to investigate high‐temperature high‐pressure chemical reactions iron nitride Fe 2 N with nitrogen. At pressures between 10 45 GPa, significant magnetic hyperfine splitting indicated compound formation after annealing at 1300 K. Subsequent in situ X‐ray diffraction reveals a new modification FeN NiAs‐type crystal structure, as also rationalized by first‐principles total‐energy...
Abstract Modelling of processes involving deep Earth liquids requires information on their structures and compression mechanisms. However, knowledge the local silicates silica (SiO 2 ) melts at mantle conditions densification mechanisms is still limited. Here we report synthesis characterization metastable high-pressure phases, coesite-IV coesite-V, using in situ single-crystal X-ray diffraction ab initio simulations. Their crystal are drastically different from any previously considered...
Abstract Polynitrides are intrinsically thermodynamically unstable at ambient conditions and require peculiar synthetic approaches. Now, a one‐step synthesis of metal–inorganic frameworks Hf 4 N 20 ⋅N 2 , WN 8 Os 5 28 ⋅3 via direct reactions between elements in diamond anvil cell pressures exceeding 100 GPa is reported. The porous (Hf ) built from transition‐metal atoms linked either by polymeric polydiazenediyl (polyacetylene‐like) nitrogen chains or through dinitrogen units. Triply bound...
Abstract Metal carbides are known to contain small carbon units similar those found in the molecules of methane, acetylene, and allene. However, for numerous binary systems ab initio calculations predict formation unusual metal with exotic polycarbon units, [C 6 ] rings, graphitic sheets at high pressure (HP). Here we report synthesis structural characterization a HP-CaC 2 polymorph Ca 3 C 7 compound featuring deprotonated polyacene-like para -poly(indenoindene)-like nanoribbons,...
Abstract Transition metal nitrides, particularly those of 5 d metals, are known for their outstanding properties, often relevant industrial applications. Among these elements, tungsten is especially attractive given its low cost. In this high‐pressure investigation the W–N system, two novel ultra‐incompressible nitride superconductors, namely W 2 N 3 and , successfully synthesized at 35 56 GPa, respectively, through a direct reaction between in laser‐heated diamond anvil cells. Their crystal...
Abstract Feldspars are rock-forming minerals that make up most of the Earth’s crust. Along mantle geotherm, feldspars stable at pressures to 3 GPa and may persist metastably higher under cold conditions. Previous structural studies limited ~10 GPa, have shown dominant mechanism pressure-induced deformation is tilting AlO 4 SiO tetrahedra in a tetrahedral framework. Herein, based on results situ single-crystal X-ray diffraction 27 we report discovery new high-pressure polymorphs anorthite...
Three oxygen-free pentazolate salts Na<sub>2</sub>N<sub>5</sub>, NaN<sub>5</sub>and NaN<sub>5</sub>·N<sub>2</sub>were synthesized from sodium azide NaN<sub>3</sub>and molecular nitrogen N<sub>2</sub>at 50 GPa.