Developments of Surface Characterization System using White X-rays

针对LEED和RHEED无法在特殊环境下表征表面结构的问题，研制了一种基于白X射线的能量色散全感染X射线分析(ED-TRXA)系统，并将其应用于有机气体、紫外光等环境下的表面和薄膜分析。首先，提出并制作了由高电子密度薄膜(Au)和低衰减系数物质(Be片和超薄硅水)组成的反射透射型X射线滤光片，以开发利用白X射线测量能量色散X射线反射率(ED-XR)的技术。成功地制作了具有手摇功能的高性能X射线滤光片。利用手持式X射线滤光片进行X射线能谱测量，使X射线探测的动态范围提高了1~2个数量级。此外，在几种有机蒸气(H_2O、CH_3OH、C_2H_5IH和C_3H_6OH)中考察了光催化剂TiO2光催化剂的表面结构，以考察ED-TRXA体系的性能。有机和紫外光照射下的二氧化钛晶体表面的面内衍射峰随有机蒸气种类的不同而改变表面晶格的位移。尤其是在甲醇作用下，TiO_2(110)晶面的表面结构发生了很大的变化，这表明其具有较高的光催化活性。ED-TRXA的另一个应用是对纳米厚度的有机薄膜进行结构和取向表征，以及利用X射线表面传播波估计表面密度。从这一时期得到的结果来看，利用白X射线的ED-TRXA是一种在特殊环境下进行表面分析的有用和有力的工具。

In order to a characterize surface structures under special environments, which cannot apply LEED and RHEED, an energy dispersive total infection X-ray analysis (ED-TRXA) system using white X-rays was developed, and applied this equipment to the surface and thin film analysis under the organic gas, under ultraviolet irradiation, etc. First, reflection-transmission type X-ray filter, consisted of the high electron density thin film(Au) and low attenuation coefficient substance (Be sheet and ultra-thin Si water), was proposed and fabricated for developing energy dispersive X-ray reflectivity (ED-XR) measurement technique using white x-rays. We succeed in fabricating high performance X-ray filter with hand-pans function. By utilizing the hand-pass X-ray filter to the ED-XR measurements, dynamic range of XR detection was increased with 1-2order. In addition, the surface structures of photocatalyst TiO_2 were investigated in several kinds of organic vapor (H_2O, CH_3OH, C_2H_5IH and C_3H_6OH) to demonstrate the performances of ED-TRXA system. In-plane diffraction peaks of TiO_2 crystal surface in organic and ultraviolet irradiation invested the displacements of surface lattice depending on the kind of organic vapor. Especially, surface structures on TiO_2(110) was greatly changed under the methyl alcohol, and this result was suggested high photo-catalytic activities of TiO_2(110) plane. Another application of ED-TRXA wan structural and orientational characterization of organic thin films with nm-thickness, and surface density estimations by using X-ray surface propagation wave. From these results obtained this period, it was suggested the ED-TRXA using white x-rays is useful and powerful tool for surface analysis under the special environment.