Low temperature photoluminscence characteristics of PZT/SiO2 transparent nancomposites

Abstract

采用改进的溶胶-凝胶工艺制备了锆钛酸铅（Pb（Zr0.52Ti0.48）O3-PZT）/二氧化硅透明纳米复合材料.在740～800℃温度下热处理可得到PZT纳米微晶.X射线衍射分析表明,PZT为钙钛矿结构,而二氧化硅基体为非晶态.从10K至室温对样品进行了荧光分析,纯的二氧化硅基体在3.2eV处出现一较强的发光峰,在2.65eV处出现一较弱的发光峰.PZT微晶掺入后此两峰受到抑制,新的发光峰出现在2.3eV处,该峰随微晶尺寸的减小具有蓝移特征,表明铁电纳米粒子掺杂的纳米复合材料所产生的荧光峰强烈地依赖于微晶尺寸. Transparent Pb(Zr0.52Ti0.48)O3(PZT) doped silica nanocomposites were fabricated via a modified Sol - Gel process. The nanocomposites were annealed in different temperatures of 740~800℃ to yield nanometer - sized PZT crystallites with various crystallite sizes. XRD analysis indicated that the embedded PZT nanoparticles were crystallized with perovskite structure while the SiO2 matrix was still in an amorphous state. Photoluminescence(PL) spectra were measured at temperature ranging from 10K to room temperature. The undoped silica matrix showed a strong emission band at 3.2eV and a weak emission band at 2.65eV. They were noticeably suppressed in our PZT/SiO2 nanocomposites. An additional emission band at 2.3eV due to transition within the PZT crystallites was also observed. This emission band showed a large blueshift with decreasing PZT crystallite size. This demonstrates that the PL spectra of ferroelectric nanoparticle - doped silica have a strong dependence on crystallite size.