A5084432807- Rare-earth and actinide compounds
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- Magnetic Properties and Synthesis of Ferrites
- MXene and MAX Phase Materials
- Inorganic Chemistry and Materials
- Iron oxide chemistry and applications
- Magnetic properties of thin films
- Magnetic Properties and Applications
- Radioactive element chemistry and processing
- Superconducting Materials and Applications
- Hydrogen Storage and Materials
- Solid-state spectroscopy and crystallography
- Metallic Glasses and Amorphous Alloys
- Metal and Thin Film Mechanics
- Intermetallics and Advanced Alloy Properties
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Geological and Geochemical Analysis
- Atomic and Subatomic Physics Research
- Gold and Silver Nanoparticles Synthesis and Applications
Savannah River National Laboratory
2021-2025
Hydrogenics (Belgium)
2025
Oak Ridge National Laboratory
2018-2023
Rice University
2015-2021
Babasaheb Bhimrao Ambedkar Bihar University
2017
University of Memphis
2012-2015
Karnatak University
2011
CEA Grenoble
1994
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1994
Institut Laue-Langevin
1994
The experimental realization of magnetic skyrmion crystals in centrosymmetric materials has been driven by theoretical understanding how a delicate balance anisotropy and frustration can stabilize topological spin structures applied fields. Recently, the material Gd_{2}PdSi_{3} was shown to host field-induced crystal, but stabilization mechanism remains unclear. Here, we employ neutron-scattering measurements on an isotopically enriched polycrystalline sample quantify interactions that drive...
In quantum magnets, magnetic moments fluctuate heavily and are strongly entangled with each other, a fundamental distinction from classical magnetism. Here, inelastic neutron scattering measurements, we probe the spin correlations of honeycomb lattice magnet YbCl3. A linear wave theory single Heisenberg interaction on lattice, including both transverse longitudinal channels response, reproduces all key features in spectrum. particular, identify Van Hove singularity, clearly observable sharp...
Pure phase exchange-coupled nanocomposites of hard-soft magnetic oxides, (hard) SrFe10Al2O19(-) (soft) Ni0.75Zn0.25Fe2O4 were prepared via autocombution method. Magnetic properties the assessed as a function soft-phase content in nanocomposite. A 40% increase M(s) value was observed for nanocomposite with 30 Wt.% soft phase. linear M(r)/M(s) indicates presence enhanced exchange-coupling between hard and phases The highest ratio 0.68 obtained containing soft-phase. reduction coercieve field...
We study the correlated quantum magnet ${\mathrm{YbCl}}_{3}$ with neutron scattering, magnetic susceptibility, and heat capacity measurements. The crystal field Hamiltonian is determined through simultaneous refinements of inelastic scattering magnetization data. ground-state doublet well isolated from other levels results in an effective spin-1/2 system local easy plane anisotropy at low temperature. Cold spectroscopy shows low-energy excitations peaked 0.5 meV that are consistent...
Doping rare-earth ions into spinel ferrites can alter their electrical and magnetic properties. The present study delineates the structure–property relationship of effect terbium doping in NiFe2O4 ferrite. X-ray diffraction analysis (XRD) showed unit cell lattice expansion with increased Tb3+ content. Fourier transform infrared spectroscopy (FTIR) results indicate preferential occupancy at octahedral B site. parameters derived from room temperature hysteresis loops where both saturation...
Ammonia is a promising candidate as liquid hydrogen energy storage medium, but it requires catalytic decomposition (ammonia cracking) to regenerate hydrogen. Recently developed trimetallic ruthenium-potassium-promoter (RuKM) ammonia catalysts have exceptionally low temperatures, able perform the 250 °C, which significantly lower than other known that require temperatures above 500 °C. However, effects of RuKM precursor on activity not been investigated. We report observed differences 3%...
The discovery of rare-earth i-MAX phases, denoted by the general formula (RE1/3 Mo2/3)2AlC offers a new class materials that exhibit unique magnetic and structural properties. These showcase combination frustration ordering attributed to their distinct, atomically layered, ordered structure. Moreover, this phase is used as precursor for synthesis two-dimensional MXenes materials, which exciting prospects development types conductive, magnetic, or electrochemical at nanoscale. phases were...
Because of the scarcity protactinium and challenges associated with its separation crystallization, even in sulfuric acid media where is relatively stable, there has been an incomplete understanding structural features complexes. The characterization sulfate complexes limited to those solution, which have left key details unaddressed since 1960s. This report describes a synthetic strategy crystallize complex using boric acid. Herein, authors detail results hydrothermal synthesis...
Single crystals of Lu3T4Ge13–x (T = Co, Rh, Os) and Y3T4Ge13–x Ir, have been grown using the self-flux method found to adopt Yb3Rh4Sn13–x structure type. Magnetization specific heat measurements confirm that all compounds are bulk superconductors, some with reduced superconducting gaps determined from suggesting multiband superconductivity. However, an unusual increase electrical resistivity a decrease charge carrier density on cooling in normal state observed for six even though functional...
Optoelectronic devices based on lanthanide-containing materials are an emergent area of research due to imminent interest in a new generation diode materials, optical and magnetic sensors, ratiometric thermometers. Tailoring material properties through the employment photo- or thermochromic moieties is powerful approach that requires deep fundamental understanding possible cooperativity between lanthanide-based metal centers integrated switchable units. In this work, we probe concept...
Novel near infrared-absorbing iron oxide-gold core-shell nanoparticles in pin shapes were synthesized. The nanopins are superparamagnetic, with 35-fold better surface enhanced Raman scattering activities than the conventional nanospheres and 50-fold greater photothermal properties solid gold nanorods. will have important impact on medical imaging, molecular diagnostics disease treatment.
Compounds adopting the Yb3Rh4Sn13 structure type have drawn attention because of revelation exotic states such as heavy fermion behavior, superconductivity, charge density wave, and quantum critical behavior. The prototypical has historically been modeled with a primitive cubic space group, Pmn; however, structural studies led to realization disordered atomic sites, requiring lower symmetry models. We will review low models required describe distortions in related type. In addition, we...
The crystalline electric field (CEF) of ${\mathrm{Ce}}^{3+}$ in trigonal symmetry has recently become some relevance, for instance, the search frustrated magnetic systems. Fortunately, it is one CEF cases which a manageable analytic solution can be obtained. Here, we present this general case, and use result to determine scheme new compound ${\mathrm{CeIr}}_{3}{\mathrm{Ge}}_{7}$ with help $T$-dependent susceptibility isothermal magnetization measurements. resulting parameters...
We show that Ce- and Yb-based Kondo-lattice ferromagnets order mainly along the magnetically hard direction of ground-state Kramers doublet determined by crystalline electric field. Here, we argue this peculiar phenomenon, was believed to be rare, is instead standard case. Moreover, it seems independent on Curie temperature ${T}_{C}$, structure, size ordered moment, type wave function. On other hand, all these systems Kondo coherence maximum in dependence resistivity just above which...
Single crystals of ${\mathrm{Yb}}_{3}(\mathrm{Rh}{}_{1\ensuremath{-}x}{T}_{x}){}_{4}{\mathrm{Ge}}_{13}$ $(T\phantom{\rule{0.5em}{0ex}}=\phantom{\rule{0.5em}{0ex}}\mathrm{Co},\phantom{\rule{0.16em}{0ex}}\mathrm{Ir})$ have been grown using the self-flux method. Powder x-ray diffraction data on these compounds are consistent with cubic structure space group $Pm\overline{3}n$. Intermediate-valence behavior is observed in upon $T$ = Co doping, while Ir doping drives system into a heavy-fermion...
Spin-1/2 chains with alternating antiferromagnetic (AF) and ferromagnetic (FM) couplings exhibit quantum entanglement like the integer-spin Haldane might be similarly utilized for computations. Such AF-FM have been proposed to realized in distorted honeycomb-lattice compound Na$_2$Cu$_2$TeO$_6$, but confirm this picture a comprehensive understanding of exchange interactions including terms outside idealized model is required. Here we employ neutron scattering study spin dynamics...