Under zero magnetic field, antiferro-quadrupole ordering in CeBe 6 has been observed for the first time by means of resonant x-ray scattering(RXS) technique. The RXS is observed at the 2p-5d dipole transition energy of the Ce I/3-edge. A possibility of determination of the various type of the induced quadrupole ordered state at (1/2, 1/2, 1/2) is also discussed on the basis of the model calculation of azimuthal anlge dependence of the RXS intensity.
- Antiferro-quadrupole ordering
- Magnetic phase diagram
- Orbital ordering
- Resonant X-ray scattering