Spin Order Research Team

An electron in materials with a negative electrical charge also behaves as a tiny magnet termed spin. A material therefore becomes a magnet when the majority of electrons have spins in one direction. In addition to this well-known phenomenon, recent researches are suggesting that some types of spin order should cause other extraordinary phenomena; spontaneous polarization of electrical charges (ferroelectricity) or difference in color of material between the front and back sides (directional dichroism) . We will research spin arrangements by using X-ray which has wavelength with the same order as atomic spacing. Our studies on relationship between functions of materials and spin arrangements provide useful information for exploration of novel functional materials.

Research Subjects

• Magnetic structure analyses by magnetic scattering of polarized x-ray beam
• Study on nonreciprocal magneto-x-ray phenomena
• Study on spin/orbital order by resonant x-ray scattering
• Real-space imaging of phase coexistence/multi-domain states by scanning x-ray diffraction

Publications

1. Yamasaki, Y., Sagayama, H., Goto, T., Matsuura, M., Hirota, K., Arima, T., and Tokura, Y.:
   "Electric Control of Spin Helicity in a Magnetic Ferroelectric"
   Phys. Rev. Lett. 98 147204 (2007)
2. Arima, T., Yamasaki, Y., Goto, T., Iguchi, S., Ohgushi, K., Miyasaka, S., and Tokura, Y.:
   "Spin-Lattice Coupling in Ferroelectric Spiral Magnets: Comparison between the Cases of (Tb,Dy)MnO3 and CoCr2O4"
   J. Phys. Soc. Jpn. 76 023602 (2007)
3. Arima, T., Tokunaga, A., Goto, T., Kimura, H., Noda, Y., and Tokura, Y.:
   "Collinear to Spiral Spin Transformation without Changing the Modulation Wavelength upon Ferroelectric Transition in Tb1-xDyxMnO3"
   Phys. Rev. Lett. 96 097202 (2006)
4. Arima, T., Goto, T., Yamasaki, Y., Miyasaka, S., Ishii, K., Tsubota, M., Inami, T., Murakami, Y., and Tokura, Y.:
   "Magnetic-field-induced transition in the lattice modulation of colossal magnetoelectric GdMnO3 and TbMnO3 compounds"
   Phys. Rev. B 72 100102R(1)-(4) (2005)
5. D. Okuyama, S. Ishiwata, Y. Takahashi, K. Yamauchi, S. Picozzi, K. Sugimoto, H. Sakai, M. Takata, R. Shimano, Y. Taguchi, T. Arima, Y. Tokura:
   "Magnetically driven ferroelectric atomic displacements in orthorhombic YMnO3"
   Phys. Rev. B 84, 054440 (2011)
6. Kim, B. J.,. Ohsumi, H., Komesu, T., Sakai, S., Morita, T., Takagi, H., Arima, T.:
   "Phase-Sensitive Observation of a Spin-Orbital Mott State in Sr2IrO4"
   Science 323, 1329-1332 (2009)
7. Kousaka, Y., Ohsumi, H., Komesu, T., Arima, T., Takata, M., Sakai, S., Akita, M., Inoue, K., Yokobori, T., Nakao, Y., Kaya, E., Akimitsu, J.
   "Crystallographic Chirality of CsCuCl3 Probed by Resonant Circularly Polarized Hard X-ray Diffraction"
   J. Phys. Soc. Jpn. 78, 123601 (2009)
8. Kajimoto, R., Sagayama, H., Sasai, K., Fukuda, T., Tsutsui, S., Arima, T., Hirota, K., Mitsui, Y., Yoshizawa, H., Baron, A. Q. R., Yamasaki, Y., Tokura, Y.:
   "Unconventional Ferroelectric Transition in the Multiferroic Compound TbMnO3 Revealed by the Absence of an Anomaly in c-Polarized Phonon Dispersion"
   Phys. Rev. Lett. 102, 247602 (2009)
9. H. Sagayama, N. Abe, K. Taniguchi, T. Arima, Y. Yamasaki, D. Okuyama, Y. Tokura, S. Sakai, T. Morita, T. Komesu, H. Ohsumi, M. Takata:
   "Observation of Spin Helicity Using Nonresonant Circularly Polarized X-ray Diffraction Analysis"
   J. Phys. Soc. Jpn. 79, 043711 (2010)
10. H. Sakai, J. Fujioka, T. Fukuda, D. Okuyama, D. Hashizume, F. Kagawa, H. Nakao, Y. Murakami, T. Arima, A. Q. R. Baron Y. Taguchi, Y. Tokura:
    "Displacement-Type Ferroelectricity with Off-Center Magnetic Ions in Perovskite Sr1-xBaxMnO3"
    Phys. Rev. Lett. 107, 137601 (2011)