4f6→4f55d1 absorption spectrum analysis of Sm2+:SrCl2

The 4f(6)-> 4f(5)5d(1) absorption spectrum of the Sm2+ ions incorporated in a SrCl2 single crystal was recorded at 4.2 K in the 15 000-45 000 cm(-1) spectral range. The overall spectrum is very satisfactorily simulated by theoretical calculations performed in the frame of the semi-empirical Hamiltonian model. The calculations enabled the assignment of all bands observed in the spectrum as well as a prediction of some experimentally unobserved transitions in the 45 000-55 000 cm(-1) region. The rich vibronic structure observed for absorption bands in the 15 000-25 000 cm(-1) spectral region is dominated by the vibronic progressions in the totally symmetric Sr-Cl stretching mode of similar to 213 cm(-1) upon the thirteen zero phonon lines and local vibration modes at similar to 81 cm(-1) and similar to 116 cm(-1). This multiphonon vibronic spectrum is very well reproduced by the model calculation.