Theoretical and Structural Study of Axial Symmetry Ce3+ Centers in the BaWO4 Single Crystal Doped with Cerium and Codoped with Sodium Ions

Materials (Basel). 2022 Aug 20;15(16):5749. doi: 10.3390/ma15165749.

Abstract

The spin-Hamiltonian parameters g-factors (g|| and g⟂) of the Ce3+ paramagnetic centers in BaWO4: Ce and BaWO4: Ce, Na single crystals with axial symmetry are investigated using the superposition model (SPM) via complete diagonalization procedure of energy matrix (CDM method). The calculated g-factors are in reasonable agreement with the experimental values. The fitted intrinsic parameters are comparable with data from other publications for rare-earth paramagnetic centers in a similar environment. The angular distortions of the cerium dodecahedron [CeO8] are also studied. Structural analysis of paramagnetic centers with axial symmetry through the postulated cerium barium tetrahedron [CeBa4] connected via oxygens bridges was carried out. The mechanism of the charge compensation and the role of the second dopant (Na+) is also discussed.

Keywords: BaWO4; Ce3+; Na+; crystal field theory; electron paramagnetic resonance (EPR); spin Hamiltonian; tetragonal symmetry.

Grants and funding

This research received no external funding.