Infrared absorption, laser excitation and crystal-field analyses of the C4vsymmetry centre in KY₃F₁₀doped with Pr³⁺

We report a comprehensive spectroscopic study of KY 3 F 10 doped with trivalent praseodymium. Employing both infrared absorption and laser excited fluorescence spectroscopy, we have constructed an energy level scheme of 39 crystal-field states. A C 4v symmetry, conventional crystal-field analysis can well account for the measured crystal-field splittings with the exception of the 1 D 2 levels. The inclusion of spin correlation effects improves the fit significantly; however the magnitudes of the optimized parameters are not well determined.