A5034726943- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Multiferroics and related materials
- Physics of Superconductivity and Magnetism
- Ferroelectric and Piezoelectric Materials
- Nuclear Physics and Applications
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Rare-earth and actinide compounds
- Solid-state spectroscopy and crystallography
- Microstructure and Mechanical Properties of Steels
- Crystallization and Solubility Studies
- Atomic and Subatomic Physics Research
- Magnetic Properties of Alloys
- Magnetic confinement fusion research
- Electronic and Structural Properties of Oxides
- Metal Alloys Wear and Properties
- Acute Myeloid Leukemia Research
- Advanced NMR Techniques and Applications
- Microstructure and mechanical properties
- Transition Metal Oxide Nanomaterials
- Crystallography and molecular interactions
- Thermal Expansion and Ionic Conductivity
- Magnetic properties of thin films
- Metallic Glasses and Amorphous Alloys
Tohoku University
2015-2024
Kanazawa University
2024
Hokkaido University
1990-2023
Tokyo Institute of Technology
2020-2022
Osaka Prefecture University
2022
Kanagawa Industrial Technology Center
2020-2022
High Energy Accelerator Research Organization
2020
National Institute for Materials Science
2020
Osaka University
2020
Iwate University
2020
Systematic low-energy neutron-scattering studies have been performed on float-zone-grown single crystals of ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ with $x$ extending from zero doping, $x=0$, to the overdoped, weakly superconducting regime, $x=0.25$. For beyond a critical doping value ${x}_{c}\ensuremath{\approx}0.05$ spin-fluctuation peak position shifts ($\frac{1}{2}$, $\frac{1}{2}$) ($\frac{1}{2}$\ifmmode\pm\else\textpm\fi{}\ensuremath{\delta},...
A lightly doped manganite ${\mathrm{La}}_{0.88}{\mathrm{Sr}}_{0.12}{\mathrm{MnO}}_{3}$ exhibits a phase transition at ${T}_{\mathrm{OO}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}145\phantom{\rule{0ex}{0ex}}\mathrm{K}$ from ferromagnetic metal ( ${T}_{C}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}172\phantom{\rule{0ex}{0ex}}\mathrm{K}$) to novel insulator. We identify that the key parameter in is orbital degree of freedom ${e}_{g}$ electrons. By utilizing resonant x-ray...
Neutron-scattering measurements have been performed to search for possible elastic incommensurate magnetic peaks in superconducting ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ with $x=0.10,$ 0.12, and 0.15. The most dramatic effects are found $x=0.12;$ this case, the peak intensity first appears at onset of superconductivity ${T}_{c}(=31 \mathrm{K}).$ resolution-limited width indicates that static correlation length exceeds 200 \AA{} isotropically...
Lattice modulation and magnetic structures in magnetoelectric compounds ${\mathrm{Tb}}_{1\ensuremath{-}x}{\mathrm{Dy}}_{x}{\mathrm{MnO}}_{3}$ have been studied around the ferroelectric (FE) Curie temperature ${T}_{C}$ by x-ray neutron diffraction. Temperature-independent vectors through are observed for with $0.50\ensuremath{\le}x\ensuremath{\le}0.68$. This indicates that ferroelectricity a polarization ($P$) along $c$ axis $R{\mathrm{MnO}}_{3}$ series cannot be ascribed to such an...
The magnetic and ferroelectric properties of multiferroic RMn2O5 (R = Y, Tb, Ho, Er, Tm) are reviewed based on recent neutron diffraction dielectric measurements. Successive phase transitions ordering were found to occur simultaneously in this system. characteristic the system exhibits an incommensurate–commensurate transition, again incommensurate phase. Special attention is given structure order discuss mechanism for introduction polarization. For all compounds examined, spin configuration...
SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 the Materials and Life Science Experimental Facility of Japan Accelerator Research Complex (J-PARC). The was designed for precise crystal magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure field, diffraction measurements small single crystals down to 0.1 mm 3 in volume. comprises three choppers, an elliptical shape straight supermirror guide, vacuum...
We report a neutron diffraction study of the magnetic field- and impurity-induced ferroelectric states triangular lattice antiferromagnet CuFe 1- x Al O 2 . The structure phase was elucidated to be not cycloidal structure, which can successfully lead electric polarization through formula P ∝ e i j ×( S × ) [H. Katsura et al. : Phys. Rev. Lett. 95 (2005) 057205], but proper helical structure. Nevertheless, fact that ordering appears only in among various magnetically ordered phases strongly...
How magnetoelectric coupling actually occurs on a microscopic level in multiferroic BiFeO${}_{3}$ is not well known. By using high-resolution single crystal neutron diffraction techniques, we have determined the electric polarization of each individual element BiFeO${}_{3}$, and concluded that magnetostrictive suppresses at Fe site below ${T}_{N}$. This negative appears to outweigh spin current contributions arising from cycloid structure, which should produce positive coupling.
We conducted X-ray diffraction study of YMn 2 O 5 single crystals with an orbital--radiation source to determine the lattice distortions related ferroelectric phase transition. At present, no anomaly temperature dependence parameters has been detected around transition point T CE = 39 K within accuracy parameters, - 1 10 m 4 Å. Moreover neither splitting Bragg peaks nor appearance a super reflection were noticed below . These facts indicate that ionic displacement at is much smaller in than...
Magnetic ordering around the ferroelectric transition temperature T C1 of weakly YMn 2 O 5 has been reinvestigated by single-crystal neutron diffraction and dielectric measurements. Besides a two-dimensionally modulated incommensurate magnetic (2D-ICM) phase with propagation vector q = ( x ,0, z ) lock-in commensurate (CM) one (1/2,0,1/4) reported previously, we observed 1D-ICM characterized ,0,1/4) ∼0.492 that appears in narrow interval ∼1 K separates 2D-ICM CM phases. Corresponding to...
Charpy type impact test, hardness measurement, optical and transmission electron microscopy were performed with Fe–P alloys (P, 0.05, 0.1, 0.5 1.0 mass%) containing various amount of carbon (0.001 to 0.18 mass%). The fracture surface was examined by Auger spectroscopy measure the degree segregation phosphorus carbon. Specimens quenched into oil from 1123 K or 1173 K.Phosphorus increases ductile-brittle transition temperature both in intergranular transgranular mode, tends suppress fracture....
Crystal and magnetic structure analyses have been performed for single crystals of multiferroic materials R Mn 2 O 5 ( = Y, Ho, Er) using the neutron diffraction technique. For all compounds, in commensurate phase, where spontaneous electric polarization occurs, was determined to be a transverse spiral spin propagating along c -axis. The results demonstrate that configuration 4+ 3+ ions is essentially same three materials, suggesting ferroelectricity phase originates from configurations...
We discovered a reversible electric polarization flop from the $a$ axis (${P}_{a}$) to $b$ (${P}_{b}$) in multiferroic ${\mathrm{TmMn}}_{2}{\mathrm{O}}_{5}$ below 5 K by applying magnetic field of approximately 0.5 T along $c$ axis. This phenomenon is first example rare-earth ($R$) compound $R{\mathrm{Mn}}_{2}{\mathrm{O}}_{5}$. magnetic-field-induced corresponds phase transition one incommensurate (ICM) ${P}_{a}$ another ICM ${P}_{b}$ phase, which equivalent an above under no field. The spin...
The mission of the National Spherical Torus Experiment (NSTX) is demonstration physics basis required to extrapolate next steps for spherical torus (ST), such as a plasma facing component test facility (NHTX) or an ST based (ST-CTF), and support ITER. Key issues are transport, steady state high β operation. To better understand electron new high- k scattering diagnostic was used extensively investigate gyro-scale fluctuations with varying temperature gradient scale length. Results from n = 3...
By extensive studies of both neutron and synchrotron X-ray diffraction, we discover that the structure deviates from well-known Debye–Gruneissen predictions below T N in multiferroic BiFeO 3 . At same time, it exhibits a magnetoelastic effect ∼0.4%, when undergoes spiral magnetic order with an extremely long incommensurate period 630 Å. We show this additional electric polarization is proportional to intensity Bragg peaks. When subjected high fields, our experiments Monte-Carlo simulation...
Abstract Objectives The cryptic fusion oncogene NUP98::NSD1 is known to be associated with FLT3 ‐ITD mutation in acute myeloid leukemia (AML), and an independent poor prognostic factor pediatric AML. However, there are little data regarding the clinical significance of adult cohort. Methods We conducted a multicenter retrospective study investigate prevalence, characteristics, impact ‐ITD‐positive AML patients. Results In total 97 patients, six cases (6.2%) were found harbor transcript....
We report results of dielectric and neutron diffraction measurements in zero field on magnetic ordering weakly ferroelectric ErMn 2 O 5 . Around the transition temperature T C1 ∼38 K below N1 = 44 K, we observed successive phase transitions from a two-dimensionally-modulated (2D) incommensurate (ICM) with propagation vector q ( x ,0, z ) to another 1D-ICM one \(\mathbf{q} (q_x,0,\frac{1}{4})\) at 39.1 then commensurate (CM) (\frac{1}{2},0,\frac{1}{4})\) 37.7 K. These two (39.1 K) were found...
By combining neutron four-circle diffraction and polarized neutron-diffraction techniques we have determined the complex spin structures of a multiferroic ${\text{YMn}}_{2}{\text{O}}_{5}$ that exhibits two ferroelectric phases at low temperatures. The obtained magnetic structure has spiral components in both low-temperature are magnetically commensurate incommensurate, respectively. Among proposed microscopic theories for magnetoelectric coupling, our results consistent with spin-current...
We have performed neutron inelastic scattering and resonant x-ray (RIXS) at the Cu-${L}_{3}$ edge to study high-energy magnetic excitations energy transfers of more than 100 meV for overdoped ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ with $x=0.25$ $({T}_{c}=15$ K) $x=0.30$ (nonsuperconducting) using identical single-crystal samples two techniques. From constant-energy slices neutron-scattering cross sections, we identified up $\ensuremath{\sim}250$ $x=0.25$....
We report magnetic neutron-scattering measurements of incommensurate order in a superconducting single crystal ${\mathrm{La}}_{1.88}{\mathrm{Sr}}_{0.12}{\mathrm{CuO}}_{4}.$ find that the wave vectors which describe static magnetism do not lie along high-symmetry directions underlying ${\mathrm{CuO}}_{2}$ lattice. The positions elastic peaks are consistent with those found excess-oxygen doped ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4+y}.$ This behavior differs from precise low-temperature...
Low-energy spin excitations of La(1.85)Sr(0.15)Cu(1-y)Zn(y)O4 were studied by neutron scattering. In y=0.004, the incommensurate magnetic peaks show a well-defined "spin gap" below T(c). The signals at omega=3 meV decrease T(c)=27 K for y=0.008, also suggesting gap opening. At lower temperatures, however, signal increases again, implying novel in-gap state. y=0.017, vanishes and elastic appear. These results clarify that doped Zn impurities induce state, which becomes larger more static with...
Abstract Analytical expressions are derived for the complex amplitude in Fraunhofer diffraction field of an arbitrary Koch fractal with a finite range self-similarity. Results numerical evaluation intensity distribution patterns compared those obtained experimentally. It is shown that pattern can be divided into two areas, central area and periodic area, former surrounded by latter. The existence consequence inner cut-off self-similarity object fractal. On other hand, outer gives rise to...