A5083017727- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Material Dynamics and Properties
- Lanthanide and Transition Metal Complexes
- Magnetism in coordination complexes
- Crystallography and molecular interactions
- Advanced Condensed Matter Physics
- Metallic Glasses and Amorphous Alloys
- High-pressure geophysics and materials
- Rare-earth and actinide compounds
- Thermodynamic and Structural Properties of Metals and Alloys
- Glass properties and applications
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Advanced NMR Techniques and Applications
- Iron-based superconductors research
- Multiferroics and related materials
- Quantum many-body systems
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Electron Spin Resonance Studies
- Magnetic and transport properties of perovskites and related materials
- Organic and Molecular Conductors Research
- Quantum, superfluid, helium dynamics
- Phase Equilibria and Thermodynamics
Heinz Maier-Leibnitz Zentrum
2010-2022
Technical University of Munich
2011-2022
NIST Center for Neutron Research
2021
National Institute of Standards and Technology
2021
University of Maryland, College Park
2021
Kyoto University
2021
The University of Tokyo
2021
Centre National de la Recherche Scientifique
2006-2013
Institut Laue-Langevin
2013
Université Paris-Sud
2013
The syntheses, structures, and magnetic properties of four new complex salts, (PPN){[MnIII(salphen)(MeOH)]2[MIII(CN)6]}·7MeOH (Mn2M·7MeOH) (M = Fe, Ru, Os Co; PPN+ bis(triphenylphosphoranylidene)ammonium cation; H2salphen N,N′-bis(salicylidene)-1,2-diaminobenzene), a mixed metal Co/Os analogue (PPN){[MnIII(salphen)(MeOH)]2[CoIII0.92OsIII0.08(CN)6]}·7MeOH were undertaken. It was found that all compounds exhibit switchable single-molecule magnet (SMM) exchange-bias behavior depending on the...
Abstract Total control over the electronic spin relaxation in molecular nanomagnets is ultimate goal design of new molecules with evermore realizable applications spin-based devices. For single-ion lanthanide systems, strong spin–orbit coupling, potential are linked to energetic structure crystal field levels and quantum tunneling within ground state. Structural engineering timescale these events via appropriate fields represents a fundamental challenge for synthetic chemist, since tunnel...
We present comprehensive investigations on a pyrochlore antiferromagnet Na${}_{3}$Co(CO${}_{3}$)${}_{2}$Cl. Performed dc magnetization indicates broad maximum at around 4 K. The field dependence of the peak temperature this follows de Almeida--Thouless line, suggesting spin-glass-like phase transition. ac susceptibility measurements determine glassy transition to be 4.5 K and reveal frequency-independent 17 specific heat shows sharp 1.5 hump 5 K, which are attributed long-range magnetic...
Abstract The rational design of the magnetic anisotropy molecular materials constitutes a goal primary importance in magnetism. Indeed, applications nanomagnets, such as single‐molecule magnets and refrigerants, depend on full control over this property. Axially anisotropic systems are frequently classified easy axis or plane, depending whether lowest energy is obtained by application field parallelly perpendicularly to unique axis. Here, three lanthanide complexes studied function...
Goethite (α-FeOOH) is a common nanocrystalline antiferromagnetic mineral. However, it typically difficult to study the properties of isolated single-crystalline goethite nanoparticles, because has strong tendency form particles aggregated nanograins often with low-angle grain boundaries. This nanocrystallinity leads complex magnetic that are dominated by fluctuations in interacting grains. Here we present 5.7 nm use magnetization measurements, inelastic neutron scattering and Mossbauer...
Structurally similar, magnetically diverse: The exchange and Zeeman parameters of two dimetallic, six-coordinate cobalt(II) compounds—i.e., with orbitally degenerate metal ions—have been determined by a combination high-resolution EPR INS spectroscopies, together ab intio calculations. It is suggested that the correlation between local crystal field about CoII centers superexchange pathway controls magnetic interaction.
A spin liquid is a new state of matter with topological order where the moments continue to fluctuate coherently down lowest temperatures rather than develop static long-range magnetic as found in conventional magnets. For behavior arise material Hamiltonian must be ``frustrated'', combination lattice geometry, interactions, and anisotropies gives rise competing arrangements ground state. Theoretical Hamiltonians which produce liquids are ice, Kitaev honeycomb model, kagome antiferromagnet....
We studied Cu self-dynamics and liquid density of Zr66.7Cu33.3, Zr35.5Cu64.5, Zr36Cu64, Zr38.2Cu61.8 liquids using a combination containerless processing techniques quasielastic neutron scattering. show that the composition dependence is qualitatively controlled by packing density. It hence monotonic within narrow range not sensitive to small variations. Similarly, replacing Ni results in slower atomic dynamics Zr-Ni liquids, as consequence more dense packing. This contrast strong...
The microscopic transport and the macroscopic flow behavior of Zr-(Co,Ni)-Al melts are systemically investigated using containerless processing techniques. A remarkable decrease Co, Ni self-diffusion coefficient increase melt viscosity upon alloying Al, observed. In contrast to many other metallic glass-forming liquids, average packing fraction derived from measured density decreases. Our study indicates that chemical interactions Al with transition metal atoms play an important role in...
Abstract Quasielastic neutron scattering (QENS) is an ideal technique for studying water transport and relaxation dynamics at pico- to nanosecond timescales length scales relevant cellular dimensions. Studies of high pressure dynamic effects in live organisms are needed understand Earth’s deep biosphere biotechnology applications. Here we applied QENS study Shewanella oneidensis ambient (0.1 MPa) (200 using H/D isotopic contrast experiments normal perdeuterated bacteria buffer solutions...
Changing the number of carbon atoms in substituents ionic liquids (ILs) is a way to shift balance between Coulomb and van der Waals forces and, thus, tune physicochemical properties. Here we address this topic on microscopic level by employing quasielastic neutron scattering (QENS) provide information about stochastic motions N-alkylpyridinium based ILs relatively expanded time range, from short (subpicosecond) particle rattling long diffusive regime (hundreds picoseconds). We have...
We present progress towards a complete system for neutron polarization analysis on time-of-flight (TOF) spectrometer with large area/angle detector array. Finite element calculations have been used to model the field gradients of newly proposed PASTIS coil set, which uses wide-angle banana shaped 3He Neutron Spin Filter cell (NSF) cover scattering solid angle. The final goal this insert is enable X-Y-Z be installed future hot/thermal time-of flight spectrometers, although method also...
The pseudo-ternary solid solution CeNi(9)Ge(4-x)Si(x) (0 ≤ x 4) has been investigated by means of x-ray diffraction, magnetic susceptibility, specific heat, electrical resistivity, thermopower and inelastic neutron scattering studies. isoelectronic substitution germanium silicon atoms causes a dramatic change the relative strength competing Kondo, RKKY crystal field (CF) energy scales. strongest effect is continuous elevation Kondo temperature T(K) from approximately 3.5 K for CeNi(9)Ge(4)...
We use incoherent quasielastic neutron scattering to study the atomic dynamics of gold in a eutectic Au81Si19 melt. Despite glass-forming nature this system, self-diffusivity displays an Arrhenius behavior with low activation energy characteristic simple liquids. At high temperatures, long-range transport atoms is well described by hydrodynamic theory exponential decay self-correlation function. On cooling towards melting temperature, structural relaxation crosses over highly stretched...
Self-and chemical diffusion coefficients are reported for molten Al-Ag on the Al-rich side of phase diagram Ag concentrations up to 45at% and pure liquid Ag. Temperature dependent self-diffusion were obtained using quasi-elastic neutron scattering. Chemical measured in situ by means X-ray radiography a long-capillary furnace. A detailed error analysis experiments is reported. It shown that perturbing effects can be detected accurate with high precision. demonstrated based Al-Ag20at% Darken...
YbNi4P2 is one of the very few heavy-fermion systems which allow study ferromagnetic quantum criticality. The Curie temperature TC=0.17 K can be suppressed by substituting arsenic on phosphorus site, without changing nature ordered state. moment, even unsubstituted compound, only around 0.05 μB, hinders elastic neutron scattering experiments. To gain microscopic insight into interactions, we have studied magnetic excitations polycrystalline time-of-flight spectroscopy. For momentum transfers...
We report an inelastic neutron-scattering investigation of the longitudinal acoustic modes C${}_{60}$ chains confined inside single walled carbon nanotubes. take advantage orientations within plane pellet sample to isolate their scattering signatures in $(Q,\ensuremath{\omega})$ space, which we follow as a function temperature from 260 K up 1100 K. The results show progressive evolution chain one-dimensional (1D) crystal linear liquid, transition occurring range $\ensuremath{\sim}$150...
Elastic and inelastic neutron scattering experiments were carried out on the heavy-fermion systems CeNi8.6Cu0.4Ge4 CeNi8CuGe4 to study i) influences of Ni/Cu substitution crystal field parameters identify ii) driving forces quantum criticality in CeNi9−xCuxGe4. The relevance competing RKKY Kondo interactions changes is discussed. crystallographic site where Ni replacement by copper atoms takes place identified powder diffraction studies. Furthermore, quasi-elastic studies provide detailed...
Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well investigation materials and chemical-physical properties. For all these kinds studies, an increased neutron flux over small area needed. The prototype focusing guide component, developed produced completely at source FRM II in Garching (Germany), has been installed time-of-flight (TOF) disc-chopper spectrometer TOFTOF came into...