Superlattice structure of Ce³⁺-doped BaMgF₄ fluoride crystals - x-ray diffraction, electron spin-resonance, and optical investigations

The x-ray diffraction patterns for Ce³⁺-doped BaMgF₄ (BMF) crystals suggest the existence of superlattice structure. The superlattice model is consistent with the characterization of the 4f¹ ground state of Ce³⁺ as a probe ion using the electron spin-resonance (ESR) technique. The distinct Ce³⁺ luminescence spectra with different peak energies and lifetimes also support the superlattice model. Although the detailed superlattice structure could not be analysed using the diffraction spots, a model has been proposed, taking into account the eight Ce³⁺ polyhedra with different anion coordinations in the unit cell of the BMF crystal obtained from the ESR experiments.