Crystal field parameters for Eu3+ in KY3F10

Abstract

The fluorescence spectrum of KY₃F₁₀: 1% Eu in powder form was recorded at 77 and 4.2°K between 4600 and 7000 Å, and 89 fluorescence lines arising from levels ⁵D₀, ⁵D₁, ⁵D₂, and probably ⁵D₃ were observed. The spectrum agrees with with a C_4v symmetry, and it is possible to determine the irreducible representation of the group associated with the Stark components of ^2S+1L_J levels. The set of crystal field parameters agreeing best with the experiment, on a basis of 200 kets ‖⁷F≳, ‖⁵D≳, and ‖⁵G≳ of the 4f⁶ configuration, is B²₀=−551 cm⁻¹, B₀⁴=−1360 cm⁻¹, B⁴₄=+345 cm⁻¹, B⁶₀=394 cm⁻¹, and B⁶₄=234 cm⁻¹.