Study of the Defect Structure and Crystal-Field Parameters of α-Al₂O₃:Yb³⁺

Abstract

The methods currently used for studying the defect structure of laser host crystals doped with transition metal or rare-earth ions have several drawbacks or limitations. This study proposes an alternative approach for obtaining optimized impurity structures using molecular dynamics calculation in conjunction with the superposition model. This new approach is specifically applied to a system named α-Al₂O₃:Yb³⁺, in which the simulated defect structure is used to fit the superposition model parameters directly onto the observed energy levels. Such an approach provides predicted values of crystal-field parameters, Zeeman splitting g-factor, and hyperfine structure constants. Moreover, the C_3v site symmetry is found to be a good approximation for the actual C₃ site of Yb³⁺, as doped in an α-Al₂O₃ crystal.