Magnetic field induced 4f octupole in CeB6 probed by resonant x-ray diffraction.
A mysterious antiferroquadrupolar ordered phase of CeB6 is considered as originating from the Txyz-type magnetic octupole moment in magnetic fields. By resonant x-ray diffraction, we have verified that the Txyz-type octupole is indeed induced in the 4f orbital of Ce with a propagation vector (1/2,1/2,1/2), thereby supporting the theory. We observed an asymmetric field dependence of the intensity for an electric quadrupole (E2) resonance when the field was reversed and extracted a field dependence of the octupole by utilizing the interference with an electric dipole (E1) resonance. The result is in good agreement with that of the NMR-line splitting, which reflects the transferred hyperfine field at the boron nucleus from the anisotropic spin distribution of Ce with an Oxy-type quadrupole.
Matsumura
Takeshi
T
Department of Quantum Matter, AdSM, Hiroshima University, Higashi-Hiroshima, 739-8530, Japan. tmatsu@hiroshima-u.ac.jp
Yonemura
Takumi
T
Kunimori
Keisuke
K
Sera
Masafumi
M
Iga
Fumitoshi
F