Er3+ and Yb3+ doped BaTiO3 powders and films prepared by sol-gel method

Abstract

In this work, BaTiO3:Er3+ (0.5 and 5 mol%) and BaTiO3:Yb3+ (0.05 and 6 mol%) powders and films were prepared by the sol-gel method. The powders and films were characterized by means of FT-IR, XRD, Raman, SEM, and UV analyses. The evolution from xerogel to a BaTiO3 crystalline structure was monitored by FT-IR and XRD analyses. At 700 °C, the BaTiO3:Er3+ and BaTiO3:Yb3+ powders and films, synthesized by the sol-gel method in the presence or absence of PVP, crystallized in the cubic phase. The formation process of BaTiO3 under different synthesis conditions is discussed, based on the XRD, FT-IR, and Raman results. BaTiO3:Er3+ and BaTiO3:Yb3+ films were elaborated using the dip-coating technique. The thin films presented a good homogeneity. An optimal concentration of polyvinylpyrrolidone (PVP) allows to yield the BaTiO3 films with high thickness. PVP, which was used during the deposition to prepare BaTiO3 films, changes the rheological properties of “sol” PVP which significantly reduced the deposition steps and avoided film cracking. The powder’s morphology is characterized by particle agglomeration, with a faceted and irregular shape.