论文部分内容阅读
The infrared spectra of La_(0.65)Ba_xMnO_(3-|?￡(c) (x = 0.35, 0.33 and 0.30) were investigated experimentally. The result shows that the sample La_(0.65)Ba_xMnO_(3-|?￡(c) has the largest Curie temperature and the smallest resistivity and wave number of the stretching vibration mode of MnO_6 octaheUron at 300 K among the investigated samples. However, the absorption strength for the stretching vibration mode of Mn0_6 octahedron in La_(0.65)Ba_xMnO_(3-|?￡(c) is stronger for parainagnetic phase than that for ferromagnelic phase, which may be connected with the reducing of the dynamic in- coherent Jahn-Teller distortion below Curie temperature. In addition, the large shift of wave number for the stretching mode at the temperatures from 293 to 423 K has been observed in La_(0.65)Ba_xMnO_(3-|?￡(c), which may be due to the in- crease of the Mn-O bond length with temperature increasing.
The results show that the sample La_ (0.65) Ba_xMnO_ (3- |? C (x = 0.35, 0.33 and 0.30) were investigated experimentally. The results show that the sample La_ (0.65) Ba_xMnO_ ) has the largest Curie temperature and the smallest resistivity and wave number of the stretching vibration mode of MnO_6 octaheUron at 300 K among the investigated samples. However, the absorption strength for the stretching vibration mode of Mn0_6 octahedron in La_ (0.65) Ba_xMnO_ (3 - |? £ (c) is stronger for parainagnetic phase than that for ferromagnelic phase, which may be connected with the reducing of the dynamic in- coherent Jahn-Teller distortion below Curie temperature. In addition, the large shift of wave number for the stretching mode at the temperatures from 293 to 423 K has been observed in La_ (0.65) Ba_xMnO_ (3- | £ (c), which may be due to in-crease of the Mn-O bond length with temperature increasing.