Optical spectrum, crystal field analysis of Pr3+ in YPO4

An optical investigation of pr(3+) (1 at.%) in YPO4 single crystal is reported. The aim is an improvement of the crystal field analysis by the means of direct configuration interaction between the ground 4f(2) configuration and the nearest excited configurations. The crystal field is analyzed in the theoretical D-2d site symmetry with and without configuration interaction. The results for the associations 4f(2), 4f(2) + 4f5d, 4f(2) + 4f6p and 4f(2) + 4f5d + 4f6p are compared. The 4f(2) + 4f5d + 4f6p configuration interaction gives the smallest r.m.s. deviation between experimental and calculated energy levels, lowering it from 23.9 cm(-1) on the basis of the 91 4f(2) levels only, down to 5.8 cm(-1), when calculated on the basis of the 315 4f(2) + 4f5d + 4f6p levels. (C) 2001 Elsevier Science B.V. All rights reserved.