Photoluminescence and piezoelectricity investigation of La_1.98Nd_0.02Ti₂O₇, Sm_1.98Ce_0.02Ti₂O₇ and Er_1.98Gd_0.02Ti₂O₇ multifunctional materials

Nd³⁺ doped La₂Ti₂O₇, Ce⁴⁺ doped Sm₂Ti₂O₇ and Gd³⁺ doped Er₂Ti₂O₇ have been synthesized at different reaction temperatures using solid state reaction method, and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TG). Excitation spectra, emission spectra and decay time curves of the samples were investigated by photoluminescence spectrophotometer (PL) and typical transitions of rare earth ions were observed. Dielectric properties, piezoelectric properties and Curie temperature of the obtained luminescent materials were measured for electrical characterization. The results showed that all materials have both photoluminescent and piezoelectric properties and show high Curie temperature.