A5064524252- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Advanced Battery Technologies Research
- Electronic and Structural Properties of Oxides
- Perovskite Materials and Applications
- Supercapacitor Materials and Fabrication
- Transition Metal Oxide Nanomaterials
- Physics of Superconductivity and Magnetism
- Advancements in Solid Oxide Fuel Cells
- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- High Entropy Alloys Studies
- X-ray Diffraction in Crystallography
- Semiconductor materials and devices
- Fuel Cells and Related Materials
- Catalysis and Oxidation Reactions
- Crystallization and Solubility Studies
- Extraction and Separation Processes
- High-Temperature Coating Behaviors
- Rare-earth and actinide compounds
- Nuclear materials and radiation effects
- Gas Sensing Nanomaterials and Sensors
- Catalytic Processes in Materials Science
Oak Ridge National Laboratory
2016-2025
Future Earth
2024
Oak Ridge Associated Universities
2013-2020
Gheorghe Asachi Technical University of Iași
2020
Academy of Romanian Scientists
2020
Texas Christian University
2020
Georgia Institute of Technology
2018
General Motors (United States)
2014
Materials Systems (United States)
2014
Texas A&M University
2006-2014
Sighting of magnetic Majorana fermions? Quantum spin liquids—materials whose spins do not settle into order even at absolute zero temperature—have long captured the interest physicists. A particularly lofty goal is finding a material that can be described by so-called Kitaev model, network on honeycomb lattice harbors fermions as its excitations. Banerjee et al. present comprehensive inelastic neutron scattering study single crystals α-RuCl 3 , which has been predicted to host liquid. The...
The Kitaev model on a honeycomb lattice predicts paradigmatic quantum spin liquid (QSL) exhibiting Majorana Fermion excitations. insight that physics might be realized in practice has stimulated investigations of candidate materials, recently including alpha-RuCl3. In all the systems studied to date, non-Kitaev interactions induce magnetic order at low temperature. However, in-plane fields roughly 8 Tesla suppress long-range alpha-RuCl3 raising intriguing possibility field-induced QSL...
Single crystals of the Kitaev spin-liquid candidate $\alpha$-RuCl$_3$ have been studied to determine low-temperature bulk properties, structure and magnetic ground state. Refinements x-ray diffraction data show that low temperature crystal is described by space group $C2/m$ with a nearly-perfect honeycomb lattice exhibiting less than 0.2 \% in-plane distortion. The as-grown single exhibit only one sharp transition at $T_{N}$ = 7~K. order below this exhibits propagation vector $k$ (0, 1,...
The solid-solution metal oxide (NiMgCuZnCo)O is the first known high-entropy (HE) synthesized, forming a poster child of emerging materials, which derived from high-temperature synthesis methodologies (>900 °C). In this work, we report mechanochemical HE under ambient conditions. advantage approach was further demonstrated by introduction up to 5 wt % noble into (NiMgCuZnCo)O, as single atoms or nanoclusters, showed good stability at high temperature and produced catalytic activity in...
The high-voltage doped spinel oxides LiMn1.5Ni0.5–xMxO4 (M = Cr, Fe, and Ga; 0 ≤ x 0.08) synthesized at 900 °C have been investigated systematically before after postannealing 700 °C. Neutron diffraction studies reveal that the cation-ordered domain size tends to increase upon annealing Time-of-flight secondary-ion mass spectroscopy data dopant cations M Ga segregate preferentially surface, resulting in a more stable cathode–electrolyte interface superior cyclability both room temperature 55...
Recent calculations and experimental data suggest that understanding the local ordering behavior of Ni/Mn will be critical to optimize electrochemical properties LiNi0.5Mn1.5O4 (LNMO) high voltage spinel. In this study, we systematically controlled evolution Ni Mn in LNMO samples by annealing them at 700 °C air for different dwelling times, followed quenching room temperature. The long- short-range were analyzed combining neutron powder diffraction, X-ray diffraction (XRD), transmission...
Abstract A series of F‐substituted Na 2/3 Ni 1/3 Mn O 2− x F ( = 0, 0.03, 0.05, 0.07) cathode materials have been synthesized and characterized by solid‐state 19 23 NMR, X‐ray photoelectron spectroscopy, neutron diffraction. The underlying charge compensation mechanism is systematically unraveled absorption spectroscopy electron energy loss (EELS) techniques, revealing partial reduction from 4+ to 3+ upon F‐substitution. It revealed that not only but also participates in the redox reaction...
A strategy to enhance the catalytic activity at surface of an oxide thin film is unveiled through epitaxial orientation control oxygen vacancy concentration. By tuning direction channels (OVCs) in brownmillerite SrCoO2.5, a 100-fold improvement reduction kinetics realized that has OVCs open surface. As service our authors and readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized for online delivery, but not copy-edited...
The magnetic and transport properties of Fe-deficient ${\mathrm{Fe}}_{5}{\mathrm{GeTe}}_{2}$ single crystals (${\mathrm{Fe}}_{5\ensuremath{-}x}{\mathrm{GeTe}}_{2}$ with $x\ensuremath{\approx}0.3$) were studied the impact thermal processing was explored. Quenching from growth temperature has been previously shown to produce a metastable state that undergoes strongly hysteretic first-order transition upon cooling below $\ensuremath{\approx}100$ K. impacts properties, yielding an enhancement in...
We report measurements of optical absorption in the zig-zag antiferromagnet $\alpha$-RuCl$_3$ as a function temperature, $T$, magnetic field, $B$, and photon energy, $\hbar\omega$ range $\sim$ 0.3 to 8.3 meV, using time-domain terahertz spectroscopy. Polarized show that 3-fold rotational symmetry is broken honeycomb plane from 2 K 300 K. find sharp peak at 2.56 meV upon cooling below N\'eel temperature 7 $B=0$ we identify magnetic-dipole excitation zero-wavevector magnon, or...
Quantum interference on the kagome lattice generates electronic bands with narrow bandwidth, called flat bands. Crystal structures incorporating this can host strong electron correlations non-standard ingredients, but only if these lie at Fermi level. In six compounds CoSn structure type (FeGe, FeSn, CoSn, NiIn, RhPb, and PtTl) transition metals form a lattice. The two iron variants are robust antiferromagnets so we focus latter four investigate their thermodynamic transport properties. We...
High-entropy oxides (HEOs) have attracted great interest in diverse fields because of their inherent opportunities to tailor and combine materials functionalities. The control local order/disorder the class is by extension a grand challenge toward realizing vast potential. Here we report first examples pyrochlore HEOs with five M-site cations, for Nd2M2O7, which structure has been investigated neutron diffraction pair distribution function (PDF) analysis. average pyrochlores found be...
Abstract Wadsley–Roth phased niobates are promising anode materials for lithium‐ion batteries, while their inherently low electrical conductivity still limits rate‐capability. Herein, a novel doped Mo 1.5 W Nb 14 O 44 (MWNO) material is facilely prepared via an ionothermal‐synthesis‐assisted doping strategy. The detailed crystal structure of MWNO characterized by neutron powder diffraction and aberration corrected scanning transmission electron microscope, unveiling the full occupation 6+...
Abstract High‐entropy oxides (HEOs) composed of multiple metal elements have attracted great attention as anode materials for lithium‐ion batteries (LIBs) due to the synergistic effects various species. However, practical applications HEOs are still plagued by poor conductivity, unstable solid electrolyte interphase (SEI) and cycling stability. Herein, nanosized (FeCoNiCrMn) 3 O 4 HEO (NHEO) is prepared successfully NaCl‐assisted mechanical ball‐milling strategy. Novelly, polyacrylonitrile...
The potential solid oxide fuel cell anode material Sr2MgMoO6 adopts a √2 × 2 I1̄ superstructure of the simple perovskite cell, derived from an a0a0c- tilt system via distortion Mg- and Mo-centered octahedra. Reduction appears to be correlated with antisite disorder at either point or extended antiphase defects. degree reduction is small temperatures below 900 °C. Upon further above °C, begins decompose into reduced modeled as n = Ruddlesden−Popper phase significantly higher Mo:Mg ratio, MgO,...
Two B-site ordered double perovskites, La2LiMoO6 and Ba2YMoO6, based on the S = 1/2 ion, Mo5+, have been investigated in context of geometric magnetic frustration. Powder neutron diffraction, heat capacity, susceptibility, muon spin relaxation(_SR), 89Y NMR- including MAS data collected. deviates strongly from simple Curie-Weiss paramagnetic behavior below 150K zero-field cooled/ field cooled (ZFC/FC)irreversibility occurs 20K with a weak, broad susceptibility maximum near 5K ZFC data. A fit...
The aim of this work was to better understand the electrochemical processes occurring during cycling a lithium half-cell based on ordered mesoporous hard carbon with time-resolved in situ small-angle neutron scattering (SANS). Utilizing electrolytes containing mixtures deuterated (2H) and nondeuterated (1H) carbonates, we have addressed challenging task monitoring formation evolution solid–electrolyte interphase (SEI) layer. An occurs SEI layer discharge from composition dominated by higher...
Vanadium-doped olivine LiFePO4 cathode materials have been synthesized by a low-temperature microwave-assisted solvothermal (MW-ST) method at ≤300 °C. The samples extensively characterized neutron/X-ray powder diffraction, infrared and Raman spectroscopy, elemental analysis, electron microscopy, electrochemical techniques. compositions of the as-synthesized were found to be LiFe1–3x/2Vx□x/2PO4 (0 ≤ x 0.2) with presence small number lithium vacancies (□) charge-compensated V4+, not Fe3+,...