TY - JOUR
T1 - Raman scattering study of rare-earth hexaboride
AU - Ogita, N.
AU - Nagai, S.
AU - Udagawa, M.
AU - Iga, F.
AU - Sera, M.
AU - Oguchi, T.
AU - Akimitsu, J.
AU - Kunii, S.
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Scientific Research Priority Area “Skutterudite” (No. 15072205) and for COE Research (No. 13CE2002) of the Ministry of Education, Culture, Sports, Science and Technology, Japan. The low temperature experiments is supported by N-BARD of Hiroshima University.
PY - 2005/4/30
Y1 - 2005/4/30
N2 - The excitation-energy, polarization, pressure, and temperature dependences of Raman scattering spectra have been measured for the RB6 crystals (R=Ca2+, La3+, Ce3+, Pr3+, Sm2.6+, Gd3+, Dy3+, and Yb2+). In the Raman spectra, the extra peaks have been clearly observed at around 200cm-1, except for the Raman-active phonons and CEF excitations. The extra peaks show anomalous behavior in the temperature, polarization, and lattice parameter dependences. These anomalous behaviors originate from the vibration of the rare-earth ions in octahedral B6 cage, and the extra peaks can be assigned as the second-order Raman excitations of T1u phonon at Brillouin zone boundary. In the results of pressure dependence, the valence of all Sm ions in SmB6 becomes trivalent above 20 GPa at room temperature.
AB - The excitation-energy, polarization, pressure, and temperature dependences of Raman scattering spectra have been measured for the RB6 crystals (R=Ca2+, La3+, Ce3+, Pr3+, Sm2.6+, Gd3+, Dy3+, and Yb2+). In the Raman spectra, the extra peaks have been clearly observed at around 200cm-1, except for the Raman-active phonons and CEF excitations. The extra peaks show anomalous behavior in the temperature, polarization, and lattice parameter dependences. These anomalous behaviors originate from the vibration of the rare-earth ions in octahedral B6 cage, and the extra peaks can be assigned as the second-order Raman excitations of T1u phonon at Brillouin zone boundary. In the results of pressure dependence, the valence of all Sm ions in SmB6 becomes trivalent above 20 GPa at room temperature.
KW - Raman scattering
KW - Rare-earth hexaboride
KW - Valence change
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U2 - 10.1016/j.physb.2005.01.270
DO - 10.1016/j.physb.2005.01.270
M3 - Article
AN - SCOPUS:18244377142
VL - 359-361
SP - 941
EP - 943
JO - Physica B: Condensed Matter
JF - Physica B: Condensed Matter
SN - 0921-4526
IS - SPEC. ISS.
ER -