Raman Scattering of Neat and Mixed Crystals of IrF6: The Jahn-Teller Interaction in the Ground State.

摘要

Raman scattering data for neat and mixed crystal IrF6 samples at 77 K are reported. It is found that v(2)(eg) and v(5)(t2g) both evidence nonvanishing Jahn-Teller interactions for the gammA(8g)(4)A(2g) ground state. The linear Jahn-Teller parameters for these modes are D(2) < or = 0.001 and D(5) = 0,02. The v(5) Jahn-Teller interaction is large enough to quench an expected exciton splitting of approx. 1/20 cm almost completely. The v(2) Jahn-Teller interaction is small enough so that exciton interactions predominate; however, normal v(2) k = 0 sharp line exciton structure is not observed. Anomolous phonon behavior is observed and discussed with respect to other hexafluoride phonon data. The non-Jahn-Teller active modes v(1), v(3), v(4), v(6) are found to behave in a fashion consistent with other members of this series. (Author)