Raman scattering of rare earth hexaborides
Norio Ogita; Takumi Hasegawa; Masayuki Udagawa; Fumitoshi Iga; Satoru Kunii
Журнал:
Journal of Physics: Conference Series
Дата:
2009-06-01
Аннотация:
Raman scattering spectra were measured for the rare-earth hexaborides RB<sub>6</sub> (R Ce, Gd, or Dy). All Raman-active phonons due to B<sub>6</sub> vibrations were observed in the range 600 – 1400 cm<sup>-1</sup>. Anomalous peaks were detected below 200 cm<sup>-1</sup>, which correspond to vibrations of rare-earth ion excited by second-order Raman scattering process. The intensity and energy of the rare-earth mode decrease with decreasing temperature. This suggests that the rare-earth ion vibrates in a shallow and anharmonic potential due to the boron cage. Using the reported values of mean square displacement of rare-earth ion, we estimated the anharmonic contribution for the rare-earth vibrations.
555.6Кб