Abstract： Remarkable changes (additional peaks, frequency shift, and peak width) of Raman spectra of a La0.75Ca0.25MnO3 thin film have been observed during the paramagnetic insulator-ferromagnetic metal transition. The v1 band (230 cm-1) hardens by lattice contraction as a result of the rearrangement of MnO6 octahedra. The Jahn-Teller distortions seem to be responsible for the broadening of v2 band (485 cm-1) above the magnetic transition temperature TC. It is proposed that the 438 cm-1 vibration mode activated in the magnetic ordering state is associated with the rearrangement of MnO6 octahedra. The softening of v3 band (610 cm-1) below TC can be ascribed to the magnetic interaction that brings into spin-phonon coupling terms.
(Metal-insulator transitions and other electronic transitions)
引用本文:
LIU Yong;LI Guang;FENG Shuang-Jiu;LI Xiao-Guang. Jahn-Teller Distortions Cooperating with Magnetic Interaction in
the Raman Spectra of La0.75Ca0.25MnO3 Thin Film[J]. 中国物理快报, 2003, 20(9): 1603-1606.
LIU Yong, LI Guang, FENG Shuang-Jiu, LI Xiao-Guang. Jahn-Teller Distortions Cooperating with Magnetic Interaction in
the Raman Spectra of La0.75Ca0.25MnO3 Thin Film. Chin. Phys. Lett., 2003, 20(9): 1603-1606.
2003, Vol. 20 
