Physical Chemistry Chemical Physics, January 2019, 21(5)
The crystal-field levels of Ce3+ in a series of lanthanide aluminum perovskites have been investigated with reference to polyhedron deformation. For each compound, the corresponding ideal cuboctahedron is derived through a least-square procedure. The virtual energy levels of Ce3+ in these ideal polyhedrons are then obtained considering both crystal-field splitting and spin–orbit coupling. From comparison to real levels, we have a clear understanding of how polyhedron deformation affects the energy levels of Ce3+ in the perovskites.
Journal of Luminescence 200 (2018) 35–42
Energy of 5d-levels of Ce3+ in numerous nitrides has become available due to the development of nitride phosphors recently. In this work, we have collected data on 5d-levels of Ce3+ and reconsidered the 5d centroid shift of Ce3+ in nitrides. The uniform standard, derived from the bond valence theory and the requirement for the high stability of the coordination polyhedron, has been proposed to determine the coordination number. The relationship between the 5d centroid shift of Ce3+, the polarizability of the anions and the electronegativity of the cations is revealed. The anion polarizability is linearly related to the inverse square of the average electronegativity of the cations; and the 5d centroid shift of Ce3+ can be well predicted by virtue of crystallographic data. This paper provides a feasibility to predict luminescence properties of Ce3+-doped nitrides.