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Z. Naturforsch. 69a, 497 – 500
(2014)
doi:10.5560/ZNA.2014-0040
Investigations of the Thermal Shifts and Electron–Phonon Coupling Parameters of R1 and R2 Lines for Cr3+-doped Forsterite
1 Department of Physics, Civil Aviation Flight University of China, Guanghan, People's Republic of China
2 Department of Material Science, Sichuan University, Chengdu, People's Republic of China
Received March 18, 2014 / revised May 2, 2014 / published online July 16, 2014
Reprint requests to: W.-C. Z.; E-mail:
zhengwc1@163.com
The thermal shifts of R1 and R2 lines in Cr3+-doped forsterite (Mg2SiO4) are studied by considering both the static contribution due to lattice thermal expansion and the vibrational contribution due to electron–phonon interaction. In the studies, the thermal expansion coefficient of the Cr3+ center is assumed reasonably as that of the corresponding cluster in the host crystal. The results suggest that for R1 and R2 lines the static contributions are opposite in sign and in magnitude about 37 % and 45 %, respectively, of the corresponding vibrational contributions. The true electron–phonon coupling coefficients α′ (obtained by considering both contributions) increase by about 58 % and 81 %, respectively, for R1 and R2 lines in comparison with the corresponding parameters α obtained by considering only the vibrational contribution. It appears that for the reasonable explanation of thermal shift of spectral lines and the exact estimation of electron–phonon coupling coefficient, both the static and vibrational contributions should be taken into account.
Key words: Thermal Shift; Optical Spectrum; Electron–Phonon Coupling; Mg2SiO4; Cr3+.