Simulation of the crystal field effect on the Pr3+ ion in K2La1−xPrxCl5 ternary chlorides

Abstract

The high resolution absorption, luminescence and excitation spectra of the orthorhombic potassium lanthanum praseodymium ternary chloride, K2La1−xPrxCl5, (0.02 ≤ x ≤ 0.15) single crystals were recorded at 4, 77 and 293K with different excitation sources. The experimental 4f2 energy level scheme of the Pr3+ ion in K2LaCl5 derived from the absorption and emission spectra consisted of 86 (out of 91) Stark components. This energy level scheme was simulated by using a phenomenological crystal field (cf) model which included eight free ion and nine cf parameters according to the C2v symmetry. Despite the approximate C2v point symmetry instead of the real Cs one, the simulation yielded a very satisfactory rms deviation of 17cm−1 between the experimental and calculated energy level schemes. The results, especially the weak cf strength, are discussed taking into account the bonding characteristics in K2LaCl5.