A5029428874- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Magnetic properties of thin films
- Acoustic Wave Resonator Technologies
- High-pressure geophysics and materials
- Organic and Molecular Conductors Research
- Nuclear Physics and Applications
- Solid-state spectroscopy and crystallography
- Magneto-Optical Properties and Applications
- Magnetism in coordination complexes
- Rare-earth and actinide compounds
- Theoretical and Computational Physics
- Microwave Dielectric Ceramics Synthesis
- Electronic and Structural Properties of Oxides
- Iron-based superconductors research
- Advanced NMR Techniques and Applications
- Perovskite Materials and Applications
- Magnetic Properties of Alloys
- Dielectric properties of ceramics
- Inorganic Chemistry and Materials
- X-ray Diffraction in Crystallography
- Magnetic Properties and Synthesis of Ferrites
Comprehensive Research Organization for Science and Society
2016-2025
Osaka University
2009-2024
CROSS Neutron Science and Technology Center
2022
Tohoku University
1997-2015
Osaka Health Science University
2009-2012
Peter the Great St. Petersburg Polytechnic University
2010-2012
The University of Tokyo
2005-2010
Tokai University
2006
Oak Ridge National Laboratory
2003-2005
University of Tennessee at Knoxville
2003
Magnetic ferroelectrics or multiferroics, which are currently extensively explored, may provide a good arena to realize novel magnetoelectric function. Here we demonstrate the genuine electric control of spiral magnetic structure in one such ferroelectric, ${\mathrm{TbMnO}}_{3}$. A spin-polarized neutron scattering experiment clearly shows that spin helicity, clockwise counterclockwise, is controlled by direction spontaneous polarization and hence polarity small field applied on cooling.
Neutron scattering experiments continue to improve our knowledge of spin fluctuations in layered cuprates, excitations that are symptomatic the electronic correlations underlying high-temperature superconductivity. Time-of-flight spectrometers, together with new and varied single crystal samples, have provided a more complete characterization magnetic energy spectrum its variation carrier concentration. While appear anomalous comparison simple model systems, there is clear consistency among...
Measurements of polarized neutron scattering were performed on a S=1/2 chain multiferroic LiCu2O2. In the ferroelectric ground state with spontaneous polarization along c axis, existence transverse spiral spin component in bc plane was confirmed. When direction electric is reversed, vector chirality as defined by C_(ij)=S_(i)xS_(j) (i and j being neighboring sites) observed to be indicating that spin-current model or inverse Dzyaloshinskii-Moriya mechanism applicable even this e_(g)-electron...
Abstract Perovskite CH 3 NH PbI exhibits outstanding photovoltaic performances, but the understanding of atomic motions remains inadequate even though they take a fundamental role in transport properties. Here, we present complete dynamic picture consisting molecular jumping rotational modes and phonons, which is established by carrying out high-resolution time-of-flight quasi-elastic inelastic neutron scattering measurements wide energy window ranging from 0.0036 to 54 meV on large single...
We report a polarized-neutron-diffraction study on single crystal sample of ${\text{MnWO}}_{4}$, wherein the ferroelectricity and spiral magnetic order coexist. The direction electric polarization controls sense helix that can be detected from difference in intensities satellites for parallel antiparallel spin directions incident neutrons with respect to scattering vector. temperature dependence agrees well polarization. These results corroborate an inverse effect Dzyaloshinskii-Moriya...
We have carried out a spin-polarized-neutron study on multiferroic CuCrO 2 to clarify the origin of ferroelectricity. The neutron results demonstrate that an incommensurate proper-screw magnetic structure induces electric polarization. Not only but also oxygen location contributes ferroelectricity . polarization can be explained not by conventional spin-current model theoretical prediction proposed Arima. spin helicities reversed reversal field E in phase.
The time-of-flight (TOF) type near-backscattering spectrometer (n-BSS), DNA, with Si crystal analyzers was built and started operation in 2012 at the Materials Life Science Experimental Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). DNA is first n-BSS pulse shaping chopper installed a spallation pulsed neutron source. It offers currently highest energy-resolution about 2.4 micro eV by operating double-disk 225 Hz whose phase optimized to narrowest slit 10 mm width....
We have established the relationship between electric polarization vector and local spin arrangement including chirality in delafossite multiferroic $\mathrm{Cu}{\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x}{\mathrm{O}}_{2}$. The results of polarized neutron diffraction pyroelectric measurements demonstrate that proper helical magnetic ordering $\mathrm{Cu}{\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x}{\mathrm{O}}_{2}$ induces a spontaneous parallel to chirality. This result cannot be...
The ferroelectric state in an orthorhombic perovskite RMnO3 (R=Gd0.7Tb0.3) was proved by neutron scattering studies to show the cycloidal spin with ab-spiral plane and spin-helicity dependent polarization vector along a axis, sharing microscopic origin (inverse Dzyaloshinskii-Moriya interaction) more widely observed P||c (e.g., for R=Tb Dy) bc-spiral plane. magnetic-field induced flop from P||a as well known is thus assigned orthogonal of spiral bc ab.
We refined the magnetic structure of a ferroelectric (FE) phase multiferroic ${\text{CuFe}}_{1\ensuremath{-}x}{\text{Ga}}_{x}{\text{O}}_{2}$ with $x=0.035$ by complementary use spherical neutron polarimetry and four-circle neutron-diffraction measurement, revealing that proper-screw-type in has finite ellipticity $\ensuremath{\sim}0.9$. By means polarized in-situ pyroelectric measurements, we also investigated quantitative relationship between macroscopic polarization $(P)$ asymmetry volume...
We have used neutron diffraction to characterize the diffuse scattering in five single crystals of relaxor ferroelectric $(1\ensuremath{-}x)\mathrm{Pb}({\mathrm{Mg}}_{1∕3}{\mathrm{Nb}}_{2∕3}){\mathrm{O}}_{3}\ensuremath{-}x{\mathrm{PbTiO}}_{3}$ $(\mathrm{PMN}\text{\ensuremath{-}}x\mathrm{PT})$ with $x=0$, 10, 20, 30, and 40%. The addition ${\mathrm{PbTiO}}_{3}$ modifies well-known ``butterfly'' ``ellipsoidal'' patterns observed pure PMN $(x=0)$, which are believed be associated presence...
We measured two magnetic modes with finite and discrete energies in an antiferromagnetic ordered phase of a geometrically frustrated magnet MgCr2O4 by single-crystal inelastic neutron scattering, clarified the spatial spin correlations levels: one is hexamer other heptamer. Since these correlation types are emblematic quasielastic scattering geometric frustration, our results indicate instantaneous suppression lattice distortion spin-lattice coupling, probably also supported orbital charge....
The magnetic phase diagram of the $Y$-type hexaferrite ${\text{Ba}}_{2}{\text{Mg}}_{2}{\text{Fe}}_{12}{\text{O}}_{22}$ has been studied using single-crystal neutron diffraction. result indicates successive transitions where modulation wave number changed discontinuously when a field is applied and temperature varied. For low-temperature spin-driven ferroelectric state, we have found sixfold structure with $\mathbit{q}=(0\text{ }0\text{ }1/2)$ in weak fields twofold }3/2)$ strong between...
The phonon-dispersion relations for cubic ${\text{NaNbO}}_{3}$ have been determined along the [100], [110], and [111] directions using inelastic neutron scattering. A simultaneous softening of transverse acoustic (TA) phonon modes occurs at zone-boundary $M(0.5,0.5,0)$ $R(0.5,0.5,0.5)$ points, indicating instabilities in-phase out-of-phase rotations oxygen octahedra about [001] direction. These exhibit an extremely gradual as temperature is lowered toward ${T}_{c1}=913\text{ }\text{K}$....
We revisit the phase diagram of relaxor ferroelectric PMN-xPT using neutron powder diffraction to test suggestions that residual oxygen vacancies and/or strain affect ground state crystal structure. Powdered samples were prepared with nominal compositions x=0.10, 0.20, 0.30, and 0.40 divided into two identical sets, one which was annealed in air relieve grinding-induced promote an ideal stoichiometry. For a given composition temperature same structural is observed for each specimen. However,...
Neutron-scattering studies of (Bi${}_{1/2}$Na${}_{1/2}$)TiO${}_{3}$ (BNT) have been performed to elucidate the microscopic mechanism broad maximum in temperature dependence dielectric constant at ${T}_{\mathrm{m}}\ensuremath{\sim}600$ K and reduction piezoelectric properties above depolarization temperature, $460\ensuremath{\sim}480$ K. We observed diffuse scattering near $\ensuremath{\Gamma}$ point below 700 K, which competes with superlattice peak $M$ tetragonal phase but coexists $R$...
Understanding Li-ion conduction in superionic conductors accelerates the development of new solid electrolytes to enhance charge–discharge performances all-solid-state batteries. We performed a quasi-elastic neutron scattering study on model conductor (Li10+xGe1+xP2–xS12, LGPS), reveal its ion dynamics an angstrom-scale spatial range and pico-to-nanosecond temporal range. The observation spectra at 298 K confirmed high lithium diffusivity. obtained diffusion coefficient was order 10–6 cm2...
<title>Abstract</title> Electronic correlations lead to heavy quasiparticles in three-dimensional (3D) metals, and their collapse can destabilize magnetic moments. It is an open question whether there analogous instability one-dimensional (1D) systems, unanswered due the lack of metallic spin chain materials. We report neutron scattering measurements Density Matrix Renormalization Group calculations establishing spinons correlated metal Ti<sub>4</sub>MnBi<sub>2</sub>, confirming that its...
The unusual coexistence of two antiferromagnetic (AF) long-range orderings (LRO) in single-crystal ${\mathrm{NiS}}_{2}$ is investigated through measurements inelastic neutron scattering, specific heat, uniform magnetic susceptibility, and resistivity. Neutron scattering intensity reveals a honeycomb pattern the distribution reciprocal lattice space (continuous-line structure along Brillouin zone boundaries) extended critical temperature region ${(T}_{N1}=39.3\mathrm{K}<T<150\mathrm{K})$...
We have measured the effect of a c-axis-aligned magnetic field on long-range order insulating ${\mathrm{Nd}}_{2}{\mathrm{CuO}}_{4},$ as-grown nonsuperconducting and superconducting ${\mathrm{Nd}}_{1.85}{\mathrm{Ce}}_{0.15}{\mathrm{CuO}}_{4}.$ On cooling from room temperature, ${\mathrm{Nd}}_{2}{\mathrm{CuO}}_{4}$ goes through series antiferromagnetic (AF) phase transitions with different noncollinear spin structures. In all phases we find that applied c-axis induces canting AF but does not...
The nuclear and magnetic structure full magnon dispersions of yttrium iron garnet ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ have been studied using neutron scattering. refined is distorted to a trigonal space group $R\overline{3}$. highest-energy dispersion extends up 86 meV. observed are reproduced by simple model with three nearest-neighbor-exchange integrals between $16a$ (octahedral) $24d$ (tetrahedral) sites, ${J}_{aa}$, ${J}_{ad}$, ${J}_{dd}$, which estimated be...
We use neutron scattering to demonstrate that electron-doped superconducting ${\mathrm{Pr}}_{0.88}\mathrm{La}{\mathrm{Ce}}_{0.12}\mathrm{Cu}{\mathrm{O}}_{4\ensuremath{-}\ensuremath{\delta}}$ in the underdoped regime is electronically phase separated ground state, showing coexistence of a with three-dimensional antiferromagnetically ordered and quasi-two-dimensional spin-density wave modulation. The N\'eel temperature both antiferromagnetic phases decreases linearly increasing transition...