Structural and optical characteristics of BaTiO₃:Yb³⁺ powders

Yb³⁺ doped Barium Titanate powders were prepared by the sol-gel method in order to study their structural and luminescent properties. These powders have potential to be used to prepare films for luminescent screens. The synthesized powders were obtained at 2,4 and 8% mol Yb³⁺ doped BaTiO₃. In order to determine organic compound decomposition, weight loss, and establish the crystallization process, we performed TGA and DTA analyses. The powders were also thermally treated at temperatures ranging from 700 to 1200°C in order to study the structure evolution. Pure doped BaTiO₃ powders were carefully studied by X-ray diffraction (XRD). Observations of the powders using scanning electron microscopy (SEM) were done in order to correlate the grain size with the luminescent properties. A comparative study of the spectroscopy properties constituted by emission, absorption spectra, and fluorescence decay measurements using NIR excitation were done. The Yb³⁺ ions pairs emission was measured in the green region at about 500 nm when pumping at 940 nm.