固相法制备ZnO纳米晶的变温拉曼光谱

Raman spectra of ZnO nanocrystals at different temperatures synthesized by the technique of solid-phase reaction

通过固相反应法,制备了不同粒径的ZnO纳米晶。采用透射电镜(TEM)、选区衍射(SAED)、X射线衍射(XRD)对制备的氧化锌纳米晶性质进行研究,通过室温和变温拉曼光谱,发现二级散射2TO模(983 cm-1)的相对强度随颗粒的减小而增大,这是由于小颗粒晶体的晶格平移对称性受到一定的破坏。随着温度的降低,ZnO的E2模的频率蓝移,线宽变窄,是因为三声子的相互作用。

ZnO nanoparticles,which are synthesized by the technique of solid-phase reaction,were characterized by XRD,TEM and SAED.Their optical properties are registered via Raman spectra,The reason why the relative strength of the second order mode（983 cm-1） increases with the decrease of the diameter is that the crystal lattice＇s symmetry of the small crystal is damaged to a certain extent.As the temperature decreases,the frequency of E2 mode turns to blue-shift and the band width turn to narrow,the reason of the result is attributed to the reaction of three phonons.