Luminescence in semi-crystalline zirconium titanate doped with lanthanum

This paper aims to describe the synthesis of the semi-crystalline and crystalline powder of lanthanum doped with zirconium titanate (65/35), LZT through Pechini method. The analysis done by Raman demonstrated that semi-crystalline phase at 550 °C and crystalline phase after 600 °C were formed. The XRD pattern shows the ZrTiO4 phase formation demonstrating that La substitutions into the lattice take place. The calcined powder at different temperatures shows a semi-crystalline phase presenting photoluminescence effect when processed at low temperatures. From 300 to 400 °C a broadband is observed at 563 nm and 568 nm, respectively. Defects creation such as: Zr3+⋅VO and Ti3+⋅VO, Zr and Ti replaced by La with vacancy formation, impurities and imperfections contributed to the photoluminescence effect. However, the main emission is due to a reverse Ti4+ → O2− or/and Zr4+ →O2− transition that occur within a regular titanate or zirconate eight-fold coordination [BO8−δ], B = Zr4+, Ti4+.