Defect disorder and optical spectroscopy study of Eu-doped NaYF4 and NaYGdF4 nanoparticles

Author(s)

Calado, Claudia M. S. ; Manali, Isis F. ; Diogenis, Isabela M. S. ; Coelho, Sergio F. N. ; Texeira, Veronica C. ; de Mesquita, Bruno R. ; Oliveira, Joeslei L. ; Sigoli, Fernando A. ; Rezende, Marcos V. dos S.

• Document type: Journal article
• Source: Optical Materials; v. 137, p. 9-pg., 2023-01-31.

Abstract

Optical spectroscopy and defect disorder of Eu-doped NaYF4 and NaY(1-x)GdxF(4) structures were studied by computational and experimental methods. Atomistic modeling was used to make predictions about the intrinsic disorder, Eu doping sites, charge compensation schemes, and to predict the microssymmetry and detailed geometry of the dopant site. This information was used to calculate the crystal field parameters and obtain the 7F1 sublevels of the Eu3+ ion, which we used to discuss the local symmetry of the Eu3+ in the NaYF4 and NaYGdF4 structures. The experimental emission spectrum was obtained for NaYF4:Eu and NaYGdF4:Eu structures prepared by the thermal decomposition methodology. The theoretical spectroscopic study showed that the symmetry of the Eu3+ ions, based on the amount of non-null crystal field parameters is a slightly distorted S-6 symmetry and D-3d symmetry in the alpha-NaYF4 and alpha-NaYGdF4 structures, respectively, and a distorted C-3h symmetry in the ss-NaYF4 and ss-NaYGdF4 structures. A set of phenomenological charge factors and the 7F1 manifold split were satisfactorily reproduced in agreement with the experimental data. (AU)

• FAPESP's process: 14/50906-9 - INCT 2014: in Functional Complex Materials
• Grantee: Fernando Galembeck
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 21/06326-1 - Luminescence of lanthanide ions: an optical tool against counterfeiting
• Grantee: Fernando Aparecido Sigoli
• Support Opportunities: Regular Research Grants