本文设计了α、β和γ三种晶型的Na2TiO3晶体的制备方法,采用固相烧结技术成功制备了该晶体的上述三种晶型,并对其常温拉曼光谱进行了比较研究。对其中已知晶型结构的γ-Na2TiO3的拉曼光谱进行密度泛函理论的模拟计算,基于计算对其拉曼光谱高频区主要振动模式进行归属。运用高温原位拉曼光谱技术和X射线衍射技术对无序型亚稳态α-Na2TiO3晶体升温过程的相变及其结构变化进行了原位追踪与研究,为不同晶型的Na2TiO3晶体的温致结构演变及晶型的鉴定提供重要的实验依据。

In this paper,the synthesis conditions of α,β and γ phases of Na2TiO3 crystal were designed.Three crystal of different phases of Na2TiO3 were prepared successfully by solid-state reactions.Room temperature Raman spectra and X-ray diffraction (XRD) patterns of these crystalline samples were then recorded.The assignment of the major Raman-active vibrational modes of γ-Na2TiO3 in high-frequency region was made on the basis of density functional theory (DFT) calculation.In-situ high temperature both Raman spectroscopy and XRD method have been adopted to investigate temperature dependent phase transition and micro-structural evolution of the disordered metastable crystalline α-Na2TiO3.This work can offer experimental basis for the structural evolution and crystal phase identification of various crystals of Na2TiO3.