Computational Modeling of the Crystal‐Field Energy Levels and the Axial Zero Field Splitting Parameter for Fe ³⁺ Ions Doped in Single Crystals of YPO ₄

Computational modeling of the axial zero field splitting and crystal‐field energy levels for Fe 3+ doped YPO 4 single crystals is performed utilizing the superposition model and perturbation theory to calculate the crystal field parameters and zero‐field splitting parameter. A good agreement between the experimental value and the theoretical axial zero‐field splitting parameter D is obtained. This confirms the experimental conclusion that Fe 3+ ions replace Y 3+ ions in single crystal of YPO 4 . The crystal field parameters and the crystal field analysis (CFA) package are used to calculate the optical spectra of the Fe 3+ doped YPO 4 crystal. The empirical and computed CF energy levels are mutually consistent. Thus, the experimental result is well supported by the theoretical analysis.