离子交换法制备LiNbO_3超细粉体及其表征

Preparation of LiNbO_3 ultrafine powders by ion exchange method and its characterization

以草酸锂和草酸铌为原料,少量水为溶剂,充分研磨干燥后得到前驱体。利用红外光谱(FTIR)、热重分析(TG)技术对前驱体进行分析可知,草酸锂和草酸铌在研磨过程中发生了离子交换反应。将制备的前驱体分别在500,800℃下焙烧3 h,得到单相LiNbO3和(Li0.996Nb0.005)Nb0.999O3晶体。通过X-射线衍射仪(XRD)、扫描电镜(SEM)及FTIR对产物进行表征,当焙烧温度为500℃时得到的LiNbO3晶体,具有较高的相对结晶度(87%)和较小的粒径(<100 nm)。

The precursor was obtained by grinding the mixture of lithium oxalate and niobium oxalate in small amount of water and then drying.The precursor was analyzed by FTIR and TG analysis.The results show that an ion exchange reaction occurs between lithium oxalate and niobium oxalate during the grinding process.Single-phase LiNbO3 crystals and（Li0.996Nb0.005）Nb0.999O3 were obtained by calcining the prepared precursor at 500 ℃ and 800 ℃ for 3 h,respectively.The products were characterized by XRD,SEM and FTIR analysis.It is shown that the LiNbO3crystals with small particle size（100 nm） and high relative crystallinity（87%） can be obtained at 500 ℃.