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Theoretical calculations of thermal shifts and thermal broadenings of sharp lines and zero-field splitting for ruby. Part I. Thermal shifts of R1 and R2 lines

✍ Scribed by Ma Dong-ping; Liu Yanyun; Ma Ning; Chen Jurong


Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
153 KB
Volume
61
Category
Article
ISSN
0022-3697

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✦ Synopsis


A new theory of spectral thermal shifts (TS) has been developed. For the first time, by taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI), all the levels and the admixtures of wavefunctions within d 3 electronic configuration, the microscopic expressions for all the parameters in Raman, neighbor-level and optical-branch terms of TS due to EPI have been derived; their values for the R 1 , R 2 and ground levels of ruby have been evaluated; the contributions to TS from thermal expansion have also been calculated; and then, the unified calculation of the TS of R 1 and R 2 lines and zero-field splitting (ZFS) for the ground state and the thermal broadenings of R, R H and B line-groups have successfully been accomplished. It is found that the contributions from the second-order term of EPI Hamiltonian H (2) are dominant in Raman terms of R 1 and R 2 lines; the optical-branch terms play an important role in TS and increase rapidly with temperature and the ones of R 1 and R 2 lines have opposite signs due to the effects of neighbor levels; the neighbor-level terms are very important and it is the admixtures of wavefunctions caused by Coulomb interaction between d electrons and/or trigonal-field and/or spin-orbit interactions that make them nonzero; the contributions to TS from thermal expansion are also important.