Pressure and temperature dependence of optical phonons in La0.75Ca0.25MnO3 |
| |
| Institution: | 1. Coherentia-INFM and Dipartimento di Fisica, Università ‘La Sapienza’, Piazzale A. Moro 5, I00185 Rome, Italy;2. L.U.R.E. Laboratoire pour l''Utilisation du Rayonnement Electromagnétique, Bât 209D Centre Universitaire Paris-Sud, 91898 Orsay Cedex, France;1. Coordenação de Ciências Naturais, Universidade Federal do Maranhão, Campus VII, 65400-000 Codó, MA, Brazil;2. Departamento de Física, Universidade Federal do Ceará, PO BOX 6030, Campus do Pici, 60455-970 Fortaleza, CE, Brazil;3. Departamento de Ensino Superior, Instituto Federal de Educação Ciência e Tecnologia do Maranhão, Campus Imperatriz, 65919-050 Imperatriz, MA, Brazil;4. Departamento de Física, Universidade Federal de Minas Gerais, ICEx, 31270-901 Belo Horizonte, MG, Brazil;5. Departamento de Física, Universidade Federal de Sergipe, 49500-000 Itabaiana, SE, Brazil;1. Department of Electronic Engineering, Nanjing Vocational Institute of Mechatronic Technology, Nanjing, 211135, PR China;2. School of Electronic Engineering, Nanjing Xiaozhuang University, Nanjing, 211171, China;3. Department of Electrical and Automation, Shandong Labor Vocational and Technical College, Jinan, 250022, China;4. Nanjing SolarU Energy Saving Technology Co., Ltd., Nanjing, 210028, PR China;5. Faculty of Physics and Electronic Science, Hubei University, Wuhan, 430062, PR China;1. Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China;2. Department of Physics, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China;1. Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland;2. Leibniz-Institut für Kristallzüchtung, Max-Born-Str. 2, 12489 Berlin, Germany;1. Key Laboratory of Advanced Semiconductor Devices and Materials, School of Electronic Engineering, Xi''an University of Posts & Telecommunications, Xi''an, 710121, China;2. Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, Xidian University, Xi''an, 710071, China |
| |
| Abstract: | We present the results of extensive studies on Raman and infrared active phonons in the La0.75Ca0.25MnO3 manganite over a wide temperature (100–320 K) and pressure (0–14 GPa) range. The analysis of the temperature dependent data allows to identify a clear spectroscopic signature of the insulator to metal transition. Indeed the abrupt reduction of the effective electron–phonon interaction on entering the metallic phase determines a change in slope in the temperature dependence of the Jahn–Teller phonon line width. The analysis of the pressure dependent data shows that the octahedral Jahn–Teller distortion, and consequently the electron–phonon interaction, is strongly reduced only in the low-pressure regime. At very high pressure, the onset of a pressure-activated localizing mechanism efficiently contrasts the natural delocalizing tendency of pressure. We finally guess that this effect could be attributed to charge-localizing antiferromagnetic interactions activated by the strong lattice compression. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
