JOPSS - Search Results

Journal Articles

Analysis of resonant inelastic X-ray scattering at the edge in NiO

Takahashi, Manabu*; Igarashi, Junichi*; Nomura, Takuji

Physical Review B, 75(23), p.235113_1 - 235113_9, 2007/06

https://doi.org/10.1103/PhysRevB.75.235113

Times Cited Count：18 Percentile：60.66(Materials Science, Multidisciplinary)

Resonant inelastic X-ray scattering at the edge in NiO is analyzed theoretically. The antiferromagnetic groud state is described by the Hartree-Fock approximation, the core-hole potential is treated within the Born approximation, and the electron correlation effect is considered within the random-phase approximation. Consequently, the observed spectral shape and its dependence on the momentum transfer of scattered photons are explained quantitatively.

Journal Articles

Theory of resonant inelastic X-ray scattering in transition-metal compounds

Nomura, Takuji; Igarashi, Junichi*; Takahashi, Manabu*

Hoshako, 20(3), p.171 - 179, 2007/05

http://ci.nii.ac.jp/naid/10018760258

Recently, electronic excitation spectra have been observed in strongly correlated electron systems such as transition-metal compounds, by utilizing the highly brilliant synchrotron radiation. Among them, momentum dependent excitation spectra are observed in resonant inelastic X-ray scattering (RIXS) experiments at the transition-metal absorption -edge in the hard X-ray regime. The microscopic theory of RIXS constructed recently by the present authors is explained. An essential point is that RIXS spectrum is closely related to the dynamical density correlation function of correlated transition-metal electrons. Spectral shapes and momentum dependence observed in several transition-metaloxides are semiquantitatively explained.

Journal Articles

Anisotropy of resonant inelastic X-ray scattering at the edge of Si; Theoretical analysis

Nishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*

Journal of the Physical Society of Japan, 73(11), p.3171 - 3176, 2004/11

https://doi.org/10.1143/JPSJ.73.3171

Times Cited Count：3 Percentile：26.46(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

Magnetic resonant X-ray scattering at the Ga edge in UGa; A Band theoretical approach

Usuda, Manabu; Igarashi, Junichi*; Kodama, Akio*

Physical Review B, 69(22), p.224402_1 - 224402_5, 2004/06

https://doi.org/10.1103/PhysRevB.69.224402

Times Cited Count：20 Percentile：65.76(Materials Science, Multidisciplinary)

Magnetic resonant X-ray scattering (MRXS) at the edge of Ga in an antiferromagnetic phase of UGa is studied on the basis of a band-structure calculation. We find that a relatively large orbital polarization in the unoccupied states of the Ga band is induced by the orbital polarizations at neighboring U atoms through the Ga and U hybridization, and thereby leading to the large MRXS intensity.

Journal Articles

Resonant inelastic X-ray scattering at the K edge of Ge

Nishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*; Shoji, Hironobu*; Iwazumi, Toshiaki*

Journal of the Physical Society of Japan, 73(4), p.970 - 975, 2004/04

https://doi.org/10.1143/JPSJ.73.970

Times Cited Count：6 Percentile：41.19(Physics, Multidisciplinary)

no abstracts in English

Journal Articles

calculation of magnetic resonant X-ray scattering spectra in NiO

Usuda, Manabu; Takahashi, Manabu*; Igarashi, Junichi

Physical Review B, 69(1), p.014408_1 - 014408_7, 2004/01

https://doi.org/10.1103/PhysRevB.69.014408

Times Cited Count：11 Percentile：49.52(Materials Science, Multidisciplinary)

We have investigated the magnetic X-ray scattering spectra around the edge of Ni in antiferromagnetic NiO on the basis of an calculation. By taking account of orbital polarization through the spin-orbit interaction, we reproduce well the spectra obtained experimentally. We have analyzed the contributions of the resonant dipolar, quadrupolar, and non-resonant scattering processes and clarified the mechanism of the resonant magnetic X-ray scattering.

Journal Articles

X-ray magnetic circular dichroism at the edge of Mn $_{3}$ GaC

Takahashi, Manabu*; Igarashi, Junichi

Physical Review B, 67(24), p.245104_1 - 245104_5, 2003/06

https://doi.org/10.1103/PhysRevB.67.245104

Times Cited Count：23 Percentile：70.62(Materials Science, Multidisciplinary)

We theoretically investigate the origin of the X-ray magnetic circular dichroism (XMCD) spectra at the K edge of Mn and Ga in the ferromagnetic phase of Mn $_{3}$ GaC on the basis of an ab initio calculation. Taking account of the spin-orbit interaction in the LDA scheme, we obtain the XMCD spectra in excellent agreement with the recent experiment. We have analyzed the origin of each structure, and thus elucidated the mechanism of inducing the orbital polarization in the p symmetric states. We also discuss a simple sum rule connecting the XMCD spectra with the orbital moment in the p symmetric states.

Journal Articles

Resonant X-ray scattering in KCuF $_{3}$

Takahashi, Manabu*; Igarashi, Junichi

Physica B; Condensed Matter, 329-333(Part2), p.870 - 871, 2003/05

https://doi.org/10.1016/S0921-4526(02)02590-5

Times Cited Count：2 Percentile：15.16(Physics, Condensed Matter)

We study the resonant X-ray scattering (RXS) spectra around the Cu K edge in KCuF $_{3}$ on the basis of the band structure calculation combined with the LDA+U approximation. The lattice distortion is introduced as inputs of the calculation. We reproduce well the experimental spectra as a function of photon energy around the main--K--edge (MKE). The spectral structure around the MKE is independent of the magnetic order (MO) and the orbital order (OO) but strongly dependent on the magnitude of the Jahn--Teller distortion (JTD).

Journal Articles

Magnetic resonant X-ray scattering in KCuF $_{3}$

Takahashi, Manabu*; Usuda, Manabu; Igarashi, Junichi

Physical Review B, 67(6), p.064425_1 - 064425_7, 2003/02

https://doi.org/10.1103/PhysRevB.67.064425

Times Cited Count：21 Percentile：68.23(Materials Science, Multidisciplinary)

We study the magnetic resonant X-ray scattering (RXS) spectra around the K edge of Cu in KCuF $_{3}$ on the basis of an ab initio calculation. We use the full-potential linearlized augumented plane wave method in the LDA+U scheme, and introduce the lattice distortion as inputs of the calculation. We obtain finite intensity on magnetic superlattice spots by taking account of the spin-orbit interaction. We also calculate the RXS intensity on orbital superlattice spots. It is found that the intensity increases with increasing Jahn-Teller distortion.

Journal Articles

Photofission of $^{209}$ Bi at intermediate energies

Haba, Hiromitsu; Kasaoka, Makoto*; Igarashi, Manabu*; Washiyama, Koshin*; Matsumura, Hiroshi*; Oura, Yasuji*; Shibata, Seiichi*; Sakamoto, Ko*; Furukawa, Michiaki*; Fujiwara, Ichiro*

Radiochimica Acta, 90(7), p.371 - 382, 2002/08

https://doi.org/10.1524/ract.2002.90.7_2002.371

Times Cited Count：2 Percentile：17.03(Chemistry, Inorganic & Nuclear)

The reaction yields of 63 radionuclides with the mass number A = 56-135 produced in the photofission of $^{209}$ Bi by bremsstrahlung of end-point energies (E $_{0}$ ) from 450 to 1100 MeV have been measured using a catcher foil technique. The charge distribution was well reproduced by a Gaussian function with the most probable charge (Z $_{p}$ ) expressed by Z $_{p}$ = RA + S, and with the A-independent FWHME $_{CD}$ . The charge distribution parameters R, S and FWHM $_{CD}$ were independent of E $_{0}$ above 600 MeV. The weighted mean values at E $_{0}$ 600 MeV were R = 0.421 0.001, S = 0.6 0.1 and FWHM $_{CD}$ = 2.1 0.1 charge unit (c.u.). Based on the charge distribution parameters, the symmetric mass yield distributions with the most probable mass A $_{p}$ of 96 1 mass unit (m.u.) and the width FWHM $_{MD}$ of 33 1 m.u. were also obtained. The characteristics of the charge and mass yield distributions are discussed by referring to those for $^{197}$ Au based on the results of calculations using PICA3/GEM.