Study On Synthesis And Luminescent Properties Of Bismuth Layer-structured Ferroelectric Materials

In recent years,rare earth-doped ferroelectric materials have attracted much attention because of their good ferroelectric and luminescent properties.However,previous studies mainly focused on their electrical properties.Here,a series of bismuth layer-structured ferroelectric materials were successfully synthesized,and their luminescence behaviors were investigated in detail.The main research contents are listed as following:（1）A series of SrBi_4-x-yEr_xYb_yTi₄O₁₅5 upconversion nanoparticles were synthesized by a facile citrate-EDTA approach,and their microstructures and luminescent properties were investigated in detail.The thermometry performance in the visible light region was studied,and the materials exhibited high sensitivity and excellent photothermal properties.（2）A series of SrBi_3.7-xTm_xYb_0.3Ti₄O₁₅5 nanoparticles were prepared and their crystal structure,upconversion luminescence,and emission mechanism were investigated.Moreover,the thermometric behavior and photo-thermal effect were characterized in detail.（3）SrBi_3.9-xHo_xYb_0.1Ti₄O₁₅5 ceramics were prepared by a high temperature solid phase method.The luminescence regulation and photochromic properties were sysmetically studied,including response speed,control ability,and cycle stability.（4）A series of Bi_4-xEr_xTi₃O₁₂2 ceramics,which exhibited both photochromism and upconversion luminescence,were successfully synthesized.Under the stimulation of light and heat,two color states of the material can be transformed smoothly between each other and the luminescence-regulation ratio can reach upto 88%.（5）Pr-doped Bi₄Ti₃O₁₂2 ceramics were synthesized by a high-temperature solid-phase reaction.Reversible luminescence modulation was achieved by controlling the defects in the materials.Interestingly,the influence of sintering temperature on the luminescence modulation behavior has been unveiled.