Far-infrared studies of the intermediate phases in In2Se3

✍ Scribed by C. Julien; M. Eddrief

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 415 KB
• Volume: 13
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(92)90173-7

✦ Synopsis

This work reports on a study of the infrared active long-wavelength optical phonons of the layered semiconductor ln2Se 3. The temperature dependence behaviour is investigated between 10 K and 500 K, and the intermediate phases a'-and fl'-ln2Se 3 are evidenced by reflectivity measurements for the E ± c polarization in the spectral range 10-600 cm-L. At low temperature, the anomaly in the frequency and life-time of the LO mode is related with the a'-phase which is described as the frozen-in configuration of the longitudinal mode. During cooling down from the fl-ln2Se 3 phase to the a-phase, the intermediate fl'-In,Se 3 phase is formed in the temperature range 473-363 K. The formation of the superlattice is observed and a model in which the r-a phase transition is driven by acoustic phonons is proposed.