X-ray absorption fine structure analysis of functional thin films

功能薄膜的X射线吸收精细结构分析

基本信息

批准号：
08454222
负责人：
WATANABE Iwao
金额：
$ 0.9万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

Some of the thin films of a few micrometers in thickness are important materials for magnetic information storage devices, sensors, surface coating for optical devices, plating for corrosive metals, etc. In order to improve the functions of these thin films the information of their atomic scale structures is crucial. However, it is often difficult to obtain structural information of very thin films deposited on thick substrates. The purpose of this research is to investigate these thin films by X-ray absorption fine structure (XAFS) analysis which is known to be useful for studying the local atomic structure. XAFS is normally obtained by transmission method, thus it is difficult to be applied to thin films on thick substrate. Here the XAFS spectra are obtained by total-conversion electron-yield method (TCEY). Since the mean free path of Auger electrons is less than a few micrometers, TCEY-XAFS method is useful for the study of surface materials.TCEY-XAFS of deposited thin films of SrTiO_3 on single crystals, LaAIO_3 and MgO, as substrates have been studied. From the XAFS signal intensities for several samples with different thicknesses, Sr K- and Ti K-edge detecting depths are found to be 300 nm and 30 nm, respectively. The EXAFS analyses for Sr and Ti in thin films concluded that the local structure of Sr changes with the film thickness, but that of Ti does not.Amorphous iron silicates or iron nitrides are interesting magnetic materials. They can be deposited on glass by sputtering method. Their local structures are compared with those in bulk samples. The TCEY-XAFS spectroscopy is especially suitable for these amorphous deposited materials.

一些厚度的一些微米的薄膜是磁性信息存储设备，传感器，光学设备的表面涂层，用于腐蚀金属等的镀层的重要材料。为了改善这些薄膜的功能，其原子尺度结构的信息至关重要。但是，通常很难获得沉积在厚底物上的非常薄膜的结构信息。这项研究的目的是通过X射线吸收精细结构（XAFS）分析研究这些薄膜，该分析可用于研究局部原子结构。 XAF通常是通过传输方法获得的，因此很难将其应用于厚底物上的薄膜。在这里，XAFS光谱是通过总转换电子方法（TCEY）获得的。由于螺旋电子电子的平均游离路径小于几微米，因此TCEY-XAFS方法可用于研究表面材料。由于已经研究了底物，因此在单晶，LAAIO_3和MGO上沉积了Srtio_3沉积薄膜的TCEY-XAF。从XAFS信号强度的几种厚度不同的样品中，SR K-和Ti K边缘检测深度分别分别为300 nm和30 nm。 EXAFS对薄膜中SR和Ti的分析得出结论，SR的局部结构随膜厚度的变化而变化，但Ti的局部结构并非如此。强生铁硅酸盐或硝酸铁是有趣的磁性材料。它们可以通过溅射方法沉积在玻璃上。将它们的局部结构与批量样品中的结构进行比较。 TCEY-XAFS光谱法特别适合这些无定形沉积材料。