A5057924994- Inorganic Chemistry and Materials
- Crystal Structures and Properties
- Synthesis and characterization of novel inorganic/organometallic compounds
- Rare-earth and actinide compounds
- Iron-based superconductors research
- Solid-state spectroscopy and crystallography
- X-ray Diffraction in Crystallography
- Advanced Thermoelectric Materials and Devices
- Chemical Synthesis and Characterization
- Crystallization and Solubility Studies
- MXene and MAX Phase Materials
- Organometallic Compounds Synthesis and Characterization
- Thermal Expansion and Ionic Conductivity
- Zeolite Catalysis and Synthesis
- Intermetallics and Advanced Alloy Properties
- Magnetic and transport properties of perovskites and related materials
- Chalcogenide Semiconductor Thin Films
- Thermodynamic and Structural Properties of Metals and Alloys
- Organometallic Complex Synthesis and Catalysis
- Coordination Chemistry and Organometallics
- Polyoxometalates: Synthesis and Applications
- Nuclear materials and radiation effects
- Metal-Organic Frameworks: Synthesis and Applications
- Crystallography and molecular interactions
- Calcium Carbonate Crystallization and Inhibition
Max Planck Institute for Chemical Physics of Solids
2010-2025
Max Planck Society
2015-2024
TU Dresden
2007-2010
Technical University of Darmstadt
2010
Koç University
2000-2007
Istinye University
2000-2007
University of Regensburg
2005
Crystal Research (United States)
2003
Polish Academy of Sciences
2002
Włodzimierz Trzebiatowski Institute of Low Temperature and Structure Research
2002
Look, no hands! Non-supported macroscopic aerogels are fabricated from platinum, gold, and silver, bimetallic mixtures of gold/silver platinum/silver. The hydrogels consist voluminous porous networks particles or wires that only a few nanometers thick. These entirely new structures have tremendous potential for applications in catalysis nanophotonics.
The relatively small and sole micropores in zeolite catalysts strongly influence the mass transfer catalytic conversion of bulky molecules. We report here aluminosilicate ZSM-5 single crystals with b-axis-aligned mesopores, synthesized using a designed cationicamphiphilic copolymer as mesoscale template. This sample exhibits excellent hydrothermal stability. orientation mesopores was confirmed by scanning transmission electron microscopy. More importantly, mesoporous shows much higher...
${\mathrm{Eu}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ is the only clathrate known so far where guest positions are fully occupied by a rare-earth element. Our investigations show that, in addition to previously synthesized modification with clathrate-I structure, there exists second clathrate-VIII structure. Polycrystalline samples of both phases behave as local-moment ferromagnets relatively low Curie temperatures (10.5 and 36 K). The charge-carrier concentrations rather small (3.8...
Abstract The binary germanides M 12 Ge 17 and 4 9 (M Na, K, Rb, Cs) the stannides Sn were identified by a combination of direct synthesis, thermogravimetric analysis, vibrational spectroscopy, X‐ray powder data single crystal structure analysis. E phases contain cluster anions [E ] 4− in ratio 1:2, forming hierarchical with at atomic positions hexagonal Laves phase MgZn 2 . Like phases, compounds are derivatives cubic Cr 3 Si but [Ge anions. analyses give strong evidence for existence...
Biological materials are a rewarding area of modern science, yielding both evolutionary insights and inspiration for biomimetic research. In particular, biocomposite structures valuable sources novel with unusual chemical properties, they very informative the mechanisms biomineralization. Here we describe unique amorphous silica, crystalline aragonite, chitin from species order Verongida, group marine sponges. The have been analyzed diverse suite techniques, revealing chitinous template...
Abstract The reinvestigation of the crystal structure Ba 8 Ge 43 □ 3 (space group $Ia{\bar 3}d$ , no. 230; a = 21.3123(5) Å; Z 8; Pearson symbol cI 408) shows full ordering vacancies (□) in germanium framework. This ordered can be considered as derivative an ideal “Ba 46 ” clathrate‐I type ( $Pm{\bar 3}n$ ′ /2) which three (per formula unit) are allowed to order cubic superstructure with doubled unit cell parameter (□ at 24 c site, space ). In resulting framework, each vacancy is surrounded...
The single phase clathrate-I Ba(8)Ge(43)square(3) (space group Ia3d (no. 230), a = 21.307(1) A) was synthesized by quenching the melt between cold steel plates. Specimens for physical property measurements were characterized microstructure analysis and X-ray diffraction on polycrystalline samples as well crystals. Transport properties including thermopower, electrical resistivity, thermal conductivity specific heat investigated in temperature range of 2-673 K. resistivity exhibits metal-like...
A new monoclinic phase (m2) of ternary diamond-like compound Cu2SnSe3 was synthesized by reaction the elements at 850 K. The crystal structure m2-Cu2SnSe3 determined through electron diffraction tomography and refined full-profile techniques using synchrotron X-ray powder data (space group Cc, a = 6.9714(2) Å, b 12.0787(5) c 13.3935(5) β 99.865(5)°, Z 8). Thermal analysis annealing experiments suggest that is low-temperature phase, while high-temperature has cubic structure. According to...
Try to make it ordered! Micrometer-sized PbS–organic mesocrystals show a long-range order of nanoparticles within an fcc superlattice combined with preferred orientational ordering truncated octahedrally shaped PbS cores (see picture). The concept formation and structuring mesocrystalline materials is perfectly illustrated this system. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They...
Crystal growth of calcium oxalate hydrates (COM: monohydrate; COD: ‐dihydrate; COT: ‐trihydrate) is a specific example biomineralization due to their harmful role as kidney/urinary stones. In this work, the biomimetic has been achieved using double diffusion technique in agar gel matrix. In‐vitro experimental models for oxalates can give valuable information on formation Diverse morphological forms COM are grown matrices ranging from platy crystallites dumbbells and spherulites. The...
The clathrate compound Ba 6Ge25 and its relatives consist of a rigid germanium skeleton, into which barium or other metal atoms are coordinated. These guest can "rattle" freely at high temperatures, but in some them lock randomly split positions below T(S) approximately 200 K. resulting bad undergoes BCS-like superconducting transition T(c) 0.24 increases more than 16-fold, as is suppressed by hydrostatic pressure p, changes only slightly with p from 0.84 K the undistorted sister 4Na2Ge25....
The central parts of hierarchically ordered fractal aggregates fluorapatite–gelatine-composites consist an elongated hexagonal-prismatic seed (5–20 µm in length). X-ray diffraction patterns the composite-seeds (gelatine-content 2.3 wt.-%) correspond to fluorapatite single crystals, fracture area perpendicular hexagonal axis, however, shows a radial structure completely different surface pure apatite. This observation had already led assumption formation nano-composite-superstructure. Here,...
The recently discovered clathrate ${\mathrm{Ba}}_{6}{\mathrm{Ge}}_{25}$ undergoes a two-step first-order phase transition at the temperatures ${T}_{S1,S2}\ensuremath{\approx}215,$ 180 K. nature of is evidenced from hysteretical temperature dependences electrical resistivity $\ensuremath{\rho}(T),$ Hall coefficient ${R}_{H}(T),$ and magnetic susceptibility as well dependence specific heat. $\ensuremath{\rho}(T)$ increases drastically below ${T}_{S1,S2},$ but charge-carrier concentration,...
The charge carrier concentratioin is an important parameter in the search for intermetallic clathrates adequate thermoelectric applications. This work reveals influence of exact composition ${\mathrm{Eu}}_{8}{\mathrm{Ga}}_{16\ensuremath{-}x}{\mathrm{Ge}}_{30+x}$ on concentration. samples with initial ${\mathrm{Eu}}_{8}{\mathrm{Ga}}_{16}{\mathrm{Ge}}_{30}$ were processed according to two different heat treatments. Slow cooling melt and subsequent annealing produced $\ensuremath{\beta}$ phase...
Abstract The morphogenesis of calcium oxalate hydrates in aqueous solutions was investigated by varying the pH, concentration, and concentration sodium salt polyacrylate (PAA). With increasing amounts PAA solution, shape tetragonal dihydrate (COD) changes from bipyramidal through elongated prisms to dumbbells finally reverts rodlike prisms. is incorporated into prismatic zones growing COD crystals, thereby reducing growth rate {100} faces along <100> direction. Dumbbells start develop...
Single crystals of tetragonal Fe1.00Se were grown from polycrystalline material by chemical vapor transport reaction at temperatures below 723 K using AlCl3 as additive. The plate-shaped single have edge lengths up to 4 mm. display complete diamagnetic shielding factor 4piX = -1 the superconducting transition.
The new compounds K 4 Ge 9 ·9 NH 3 and Rb ·5 were prepared by the extraction of with liquid ammonia characterized low temperature X-ray structure analysis. They both contain monocapped square antiprismatic 4− anions. Cs 6 18 ·4 was 2 in presence [(Bu) MeN](Br I) as an oxidizing agent, contains a [Ge -Ge ] 6− dimer which two anions are linked single Ge-Ge bond
In one ear …︁ : The outer shape and inner architecture of individual particles a complex calcite–gelatine composite resemble the known characteristics biogenic otoconia ("ear dust"; see picture). relationships between morphology artificial specimens are discussed.
Abstract The Zintl phase Ba 3 Si 4 has been synthesized from the elements at 1273 K as a single phase. No homogeneity range found. compound decomposes peritectically 1307(5) to BaSi 2 and melt. butterfly‐shaped 6− anion in crystal structure of (Pearson symbol tP 28, space group P / mnm , = 8.5233(3) Å, c 11.8322(6) Å) shows only slightly different Si‐Si bond lengths d (Si–Si) 2.4183(6) Å (1×) 2.4254(3) (4×). is diamagnetic with χ ≈ −50 × 10 −6 cm mol −1 . DC resistivity measurements show...
BaGe(5) constitutes a new type of intermetallic clathrate obtained by decomposition clathrate-I Ba(8)Ge(43)(3) at low temperatures. The crystal structure consists characteristic layers interconnected covalent bonds. is semiconducting Zintl phase.
A new monoclinic selenide Cu5Sn2Se7 was synthesized, and its crystal electronic structure as well thermoelectric properties were studied. The of determined by electron diffraction tomography refined full-profile techniques using synchrotron X-ray powder data: space group C2, a = 12.6509(3) Å, b 5.6642(2) c 8.9319(4) β 98125(4)°, Z 2; T 295 K. Thermal analysis high-temperature indicated the decomposition at 800 K with formation tetragonal phase Cu4.90(4)Sn2.10(4)Se7: I4̅2m, 5.74738(1)...
Solely on the basis of Raman spectra and quantum chemical calculations, previously unknown cluster anion Si94- (structure shown) was characterized its structure determined. The is formed as a component solid phases by thermal decomposition alkali metal monosilicides.
Two open-framework ammonium−iron borophosphates, black colored (NH4)0.4FeII0.55FeIII0.5(H2O)2[BP2O8]·0.6H2O (1a) (pale gray 1b with a powder X-ray diffraction pattern indicating an isotype relationship was also observed) and pale pink NH4FeIII[BP2O8(OH)] (2), were synthesized under mild hydrothermal conditions at 180 °C. Their crystal structures determined by single-crystal investigations (hexagonal, P65 (no. 170), = 9.483(4) Å, c 15.697(5) V 1222.5(8) Å3, Z 6 for 1a monoclinic P21/c 14),...