2001-3

3) X-ray Diffraction Study in High Field at Low Temperature for Ce₂Fe₁₇

The thermal expansion and the structural phase transition of Ce₂Fe₁₇ have been investigated by powder X-ray diffraction measurements in the temperature range from 8 to 300K at the magnetic fields up to 5T. We observed a clear spontaneous magnetostriction in the c-axis below T_N=210K and no distinct anomaly in the a-axis at T_t=125K. We also observed a discontinuous change of the lattice parameter by applying magnetic field at low temperature. This field induced first order phase transition corresponds to the metamagnetic transition below T_t from the antiferromagnetic ground state with a helical spin structure to the induced ferromagnetic state with a fan structure. These results suggest that the hybridization between Fe 3d- and Ce 4f-electrons in Ce₂Fe₁₇ is suppressed by the application of magnetic field.

Kyushu Kyoritsu University : Yoshikazu Makihara
Hiroshima University : Hironobu Fujii, Tetsuya Fujiwara
IMR, Tohoku University : Kohki Takahashi, Kazuo Watanabe