JOPSS - Search Results

Journal Articles

Lattice distortion and resonant X-ray scattering in DyB $_{2}$ C $_{2}$

Igarashi, Junichi; Nagao, Tatsuya*

Journal of the Physical Society of Japan, 72(5), p.1279 - 1286, 2003/05

https://doi.org/10.1143/JPSJ.72.1279

Times Cited Count：13 Percentile：60.50(Physics, Multidisciplinary)

We study the resonant X-ray scattering (RXS) spectra at the Dy L_ absorption edge in the quadrupolar ordering phase of DyB $_{2}$ C $_{2}$ . Analyzing the buckling of sheets of B and C atoms, we construct an effective model that the crystal field is acting on the 5d and 4f states with the principal axes different for different sublattices. Treating the 5d states as a band and the 4f states as localized states, we calculate the spectra within the dipole transition. We take account of processes that (1) the lattice distorion directly modulates the 5d states and (2) the charge anisotropy of the quadrupole ordering 4f states modulates the 5d states through the 5d-4f Coulomb interaction. The former process is found to give dominant contribution to the spectra.

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：67.47(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

XAFS study on RbC $_{60}$

Kubozono, Yoshihiro*; Mimura, Kazue*; Takabayashi, Yasuhiro*; Maeda, Hironobu*; Kashino, Setsuo*; Emura, Shuichi*; Nishihata, Yasuo; Uruga, Tomoya*; Tanaka, Tsunehiro*; Takahashi, Masao*

Journal of Synchrotron Radiation, 6(Part3), p.564 - 566, 1999/05

The Rb K-edge XAFS spectra for the stable phase of RbC60 which is a quasi one-dimensional polymer were measured in the temperature range from 14.6 to 210 K in order to clarify the origin of the metal-insulator transition around 50 K. The distances and mean-square relative displacements between the Rb atom and the neighboring C atoms determined by XAFS exhibited no change around 50 K, implying that the metal-insulator transition originates from the SDW instablity.

Journal Articles