A5072738652- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- High-pressure geophysics and materials
- Inorganic Chemistry and Materials
- Multiferroics and related materials
- Electronic and Structural Properties of Oxides
- Intellectual Capital and Performance Analysis
- Superconductivity in MgB2 and Alloys
- ZnO doping and properties
- Heat shock proteins research
- Heusler alloys: electronic and magnetic properties
- Magnetic properties of thin films
- Coenzyme Q10 studies and effects
- Magnetic Properties of Alloys
- Corporate Taxation and Avoidance
- Magnetic Properties and Synthesis of Ferrites
- Ubiquitin and proteasome pathways
- Metal-Catalyzed Oxygenation Mechanisms
- Aldose Reductase and Taurine
- Quantum, superfluid, helium dynamics
- Boron and Carbon Nanomaterials Research
- Polysaccharides Composition and Applications
Los Alamos National Laboratory
2017-2023
Max Planck Institute for Solid State Research
2016-2022
Gwangju Institute of Science and Technology
2008-2019
Max Planck Society
2015
Thermodynamic and transport properties are reported on single crystals of the hexagonal antiferromagnet Mn3Sn grown by Sn flux technique. Magnetization measurements reveal two magnetic phase transitions at T1 = 275 K T2 200 K, below antiferromagnetic transition TN ≈ 420 K. The Hall conductivity in zero field is suppressed dramatically from 4.7 Ω−1 cm−1 to near T1, coincident with vanishing weak ferromagnetic moment. This illustrates that large anomalous effect arising Berry curvature can be...
We investigated the temperature dependence of upper critical field $[{H}_{c2}(T)]$ fluorine-free ${\text{SmFeAsO}}_{0.85}$ and fluorine-doped ${\text{SmFeAsO}}_{0.8}{\text{F}}_{0.2}$ single crystals by measuring resistive transition in low static magnetic fields pulsed up to 60 T. Both show that ${H}_{c2}(T)$'s along $c$ axis $[{H}_{c2}^{c}(T)]$ an $ab$-planar direction $[{H}_{c2}^{ab}(T)]$ exhibit a linear sublinear increase, respectively, with decreasing below superconducting transition....
We have studied the magnetic excitations of electron-doped Sr$_{2-x}$La$_x$IrO$_4$ ($0 \leq x 0.10$) using resonant inelastic x-ray scattering (RIXS) at Ir L$_3$-edge. The long range order is rapidly lost with increasing $x$, but two-dimensional short-range (SRO) and dispersive magnon nearly undiminished spectral weight persist well into metallic part phase diagram. magnons in SRO are heavily damped exhibit anisotropic softening. Their dispersions described by a pseudospin-1/2 Heisenberg...
We have used Raman scattering to investigate the magnetic excitations and lattice dynamics in prototypical spin-orbit Mott insulators ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ ${\mathrm{Sr}}_{3}{\mathrm{Ir}}_{2}{\mathrm{O}}_{7}$. Both compounds exhibit pronounced two-magnon features with different energies, line shapes, temperature dependencies, which part reflect influence of long-range frustrating exchange interactions. Additionally, we find strong Fano asymmetries shapes low-energy phonon...
Phonon softening in hexagonal BaFe12O19 single crystal is observed temperature dependent polarized Raman spectroscopy. The phonon significantly enhanced below ∼80 K, at which the magnetization a magnetic field along c-axis shows clear change dependence, indicating phase transition near 80 K. Possible interpretations of anomalous dependence frequencies–phonon behaviors are discussed. would be correlated to local structural and BaFe12O19, spin-phonon coupling have major contribution for...
Spin-orbit entangled magnetic dipoles, often referred to as pseudospins, provide a new avenue explore novel magnetism inconceivable in the weak spin-orbit coupling limit, but nature of their low-energy interactions remains be understood. We present comprehensive study static and pseudospin dynamics archetypal Mott insulator Sr2IrO4. find that order understand even basic magnetization measurements, formerly overlooked in-plane anisotropy is fundamental. In addition magnetometry, we use...
We report on the growth of stoichiometric Sr2IrO4 single crystals, which allow us to unveil their intrinsic magnetic properties. The effect different conditions has been investigated for crystals grown by flux method. find that response depends very sensitively details conditions. assess defect concentration based magnetization, X-ray diffraction, Raman scattering, and optical conductivity measurements. samples with a low electronically active defects show much reduced in-gap spectral weight...
In the non-collinear antiferromagnet Mn3Sn, we compare simultaneous measurements of anomalous Hall effect (AHE) and magneto-optical Kerr (MOKE) through two magnetic phase transitions: high-temperature paramagnetic/antiferromagnetic (AF) transition at Néel temperature (TN ≈ 420 K) a lower-temperature incommensurate ordering T1 270 K. While both AHE MOKE are sensitive to same underlying symmetries AF spin order, find that temperatures measured by these techniques unexpectedly differ...
We investigate the electronic structure of ${\text{EuFe}}_{2}{\text{As}}_{2}$ using optical spectroscopy and density-functional calculations. At low temperature we observe evolution two gaplike features, one having a weak-coupling mean-field behavior another with strongly nonmean-field behavior. Using band-structure calculations, identify former spin-Peierls-type partial gap in ${d}_{yz}$ bands latter transition across large exchange ${d}_{xz}/{d}_{xy}$ bands. Our results demonstrate that...
Sr${}_{2}$IrO${}_{4}$ is considered as a strong spin-orbit coupled equivalent of high-temperature superconducting cuprates. Recent experiments have most notably shown that upon electron doping pseudogap emerges in and magnonlike excitations survive the rapid disappearance long-range magnetic order. However, due to relatively small crystal sizes large Ir neutron cross section, information on charge magnetism has mostly been gathered using synchrotron-based spectroscopic methods. Here, authors...
Here, we report the characterization of a giant reversible anisotropic magnetocaloric effect in EuFe2As2 single crystal. The magnetic properties crystals are quite interesting; they display small hysteresis, anisotropy, and first-order phase transition. maximum entropy change in-plane magnetic-field direction was 14.6 J/kg K around 20 out-of-plane 10.3 as result changing field from 0 to 5 T. These results suggest possibility using refrigeration applications.
We herein describe our investigation of the superconducting and magnetic properties rare-earth ternary germanide intermetallic compounds La${}_{2}$Pt${}_{3}$Ge${}_{5}$ Pr${}_{2}$Pt${}_{3}$Ge${}_{5}$. Single crystals Pr${}_{2}$Pt${}_{3}$Ge${}_{5}$ were synthesized using high-temperature metal flux method. Both types crystal formed in a U${}_{2}$Co${}_{3}$Si${}_{5}$-type orthorhombic structure (space group $Ibam$). showed onset phase transition at ${T}_{c}$ $=$ 8.1 K, which, to best knowledge,...
Superconducting ternary germanide SrPd${}_{2}$Ge${}_{2}$ single crystals (${T}_{c}=$ 2.70 K) with a ThCr${}_{2}$Si${}_{2}$-type structure were synthesized using high-temperature metal flux method. Superconductivity was confirmed by temperature- and magnetic-field-dependent magnetization, electrical resistivity, heat capacity measurements. Here, weak anisotropy in superconductivity observed both parallel perpendicular to the crystallographic $c$ axis. Various parameters, such as lower upper...
The in-plane magnetic penetration depth, $\lambda_m(T)$, was measured in single crystals of SrPd$_2$Ge$_2$ superconductor a dilution refrigerator down to T=60 mK and fields up $H_{dc} = 1$ T by using tunnel diode resonator. London $\lambda$, saturates exponentially approaching $T\rightarrow 0$ indicating fully gapped superconductivity. thermodynamic Rutgers formula used estimate $\lambda(0) 426$ nm which calculate the superfluid density, $\rho_s(T)=\lambda^2(0)/\lambda^2(T)$. Analysis...
Abstract Spin-wave (magnon) scattering, when clearly observed by Raman spectroscopy, can be simple and powerful for studying magnetic phase transitions. In this paper, we present how to observe magnon scattering then apply the method study spin-ordering spin-reorientation transitions of hexagonal manganite single crystal thin films compare directly with results magnetization measurements. Our show that choosing strong resonance condition appropriate polarization configuration, temperature...
This paper investigates the magnetic and electronic properties of a single-crystal SmB4. Two phase transition temperatures at TN=25 K Tm≈7 were revealed by temperature-dependent magnetization for an applied field perpendicular to c-axis. Magnetic is caused antiferromagnetic order with Sm3+ moments that lie on ab-plain. However, temperature was not observed in along The second occurring directions both parallel c-axis suppressed applying fields. Interestingly, exhibited local maximum...
The electronic structure of SrPd${}_{2}$Ge${}_{2}$ single crystals is studied by angle-resolved photoemission spectroscopy (ARPES), scanning tunneling (STS), and band calculations within the local-density approximation (LDA). STS measurements show a $s$-wave superconducting energy gap $\ensuremath{\Delta}(0)$ $=$ 0.5 meV. photon-energy dependence observed Fermi surface reveals strongly three-dimensional character corresponding bands. By comparing experimentally measured calculated velocities...
Resonant elastic X-ray scattering is a powerful technique for measuring multipolar order parameters. In this paper, we theoretically and experimentally study the possibility of using to detect proposed parameters in URu$_2$Si$_2$ at U-$L_{3}$ edge with electric quadrupolar transition. Based on an atomic model, calculate azimuthal dependence transition edge. The results illustrate potential distinguishing different We then perform experiments ultra-clean single crystals search predicted...
We use resonant inelastic x-ray scattering (RIXS) at the Ir ${L}_{3}$ edge to study effect of hole doping upon ${J}_{\text{eff}}=\frac{1}{2}$ Mott-insulating state in ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$, via Rh replacement site. The spin-wave gap, associated with XY-type spin-exchange anisotropy, collapses increasing content, prior suppression and contrast electron La substitution Sr At same time, despite heavy damping, $d\ensuremath{-}d$ excitation spectra retain their overall amplitude...
We present a study of magnetization and transport properties single crystals YbB6 YbB6±δ (δ=0.3 as nominal value). The YbB6−δ crystal revealed weak ferromagnetism, manifested by hysteresis loop in M(H) at room temperature with saturation magnetic moment 1.5×10−4μB∕f.u. the ferromagnetic transition higher than T=300K, whereas YbB6+δ diamagnetism paramagnetism, respectively. It was found that bulk property is intrinsically diamagnetic magnetism, or paramagnetism surface effect. Based on x-ray...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTResolution of components the optical rotation tensor collagenI. V. Yannas, N. H. Sung, and C. HuangCite this: J. Phys. Chem. 1972, 76, 20, 2935–2937Publication Date (Print):September 1, 1972Publication History Published online1 May 2002Published inissue 1 September 1972https://doi.org/10.1021/j100664a030RIGHTS & PERMISSIONSArticle Views31Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are COUNTER-compliant sum full text article downloads...
Previous investigations have shown that SrPd 2 Ge , a compound isostructural with "122" iron pnictides but ironand pnictogen-free, is conventional superconductor single s-wave energy gap and strongly three-dimensional electronic structure.In this work we reveal the Abrikosov vortex lattice formed in when exposed to magnetic field by means of scanning tunneling microscopy spectroscopy.Moreover, examining differential conductance spectra across estimating upper lower critical fields...
In this study, Hall effects, magnetoresistance, and low temperature resistivity of single crystalline SrPd2Ge2 were measured. The sign change the coefficient from negative to positive with increasing in normal state violation Kohler’s rule magnetoresistance data observed. These results suggest that electrons holes would contribute together formation multi bands scattering on Fermi surface is anisotropic, which should be taken into account for transport properties SrPd2Ge2. addition, we...