Luminescence effect in amorphous PLT

Amorphous and crystalline powder of PLT phase was synthesized by using the Pechini method. Infrared (FTIR) analysis of the polymeric resin shows intense bands of organic materials from 250 to 1620 cm−1. X-ray diffraction (XRD) and Raman spectra of calcined powder at different temperatures show amorphous phase at 450 °C/3 h, semi-crystalline phase at 550 °C/3 h and a crystalline phase at 800 °C/3 h. Luminescence effect was observed in amorphous powder calcined from 300 to 350 °/3 h with broad absorption peaks in 579 nm at 300 °C/3 h and 603 nm at 350 °C/3 h, respectively. The photoluminescence effect is attributed to emissions of Ti→O directly from the oxygen 2p orbital (valence band) to the titanate 3d orbital (conduction bands).