Hydrogen retention and release dynamics in tungsten oxide layers with various structure and elemental composition

不同结构和元素组成的氧化钨层中氢的保留和释放动力学

基本信息

批准号：
18560789
负责人：
NAGATA Shinji
金额：
$ 2.49万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560789/
关键词：
plasma facing materials re-deposited layer sputtering tungsten hydrogen isotopes oxides ion irradiation optical properties

项目摘要

Tungsten oxide thin films were deposited on a SiO_2, U or St Substrates by Kt magnetron sputtering wan a pure metal W target, and by ArF - PLD using a W03 target. The substrate temperature during the deposition was varied in a range between 300 and 800 K. A mixture of argon and oxygen gases was introduced into a deposition chamber and adjusted by a mass-flow controller. The thickness of the deposited films was about 500 run. The crystal structure and microstructure of films were examined by X-ray diffractometry and by transmission electron microscopy. The composition of W and 0 in the film was determined by Rutherford Backscattering Spectroscopy (RBS). The concentration depth profiles of hydrogen were measured by the Elastic Recoil Detection Analysis (ERDA) technique. The optical absorption of the film in wavelength between 200 and 900 urn was simultaneously measured in a scattering chamber using a monochrometer equipped with CCD camera.At room temperature, poly-crystals of beta-tungsten (A-15 type structure) were formed without supplying the oxygen gas for both deposition methods. With increasing the oxygen, the long range order of the beta-tungsten was initially lost. Then an amorphous phase of W03 appeared under sufficient oxygen pressure. The ERD measurements revealed that the hydrogen atoms were uniformly distributed in the W03 film with a concentration as high as H/W = 0.7. The incorporation of hydrogen during the H2 gas exposure supports the double injection model of the gasochromic process, in which the dissolved protons. play a role for reducing Wt. During the heat treatment in a high vacuum, thermal release of hydrogen from the HxWO_3 film was completed at about 600 K, accompanied by the coloration of the film, indicating the reduction of W6 and release of H20 from the surface. The thermal release behavior of hydrogen in air atmosphere was the same as that in the vacuum, whereas the coloration of the film was suppressed.

通过KT磁铁溅射纯净的金属W靶标将氧化氧化薄膜沉积在SIO_2，U或ST底物上，并使用W03靶标的ARF -PLD。沉积过程中的底物温度在300至800 K之间变化。将氩气和氧气的混合物引入沉积室中，并由质量流控制器调节。沉积膜的厚度约为500张。通过X射线衍射法和透射电子显微镜检查膜的晶体结构和微观结构。胶片中W和0的组成由Rutherford反向散射光谱（RBS）确定。氢的浓度深度谱通过弹性后坐力检测分析（ERDA）技术测量。使用配备有CCD摄像头的单色计在散射室中同时测量膜以200至900 urn之间的波长的光吸收。两种沉积方法的氧气。随着氧气的增加，β-Tungsten的远距离顺序最初丢失了。然后，在足够的氧气压力下出现了W03的无定形相。 ERD测量结果表明，氢原子在W03膜中均匀分布，其浓度高达H/W = 0.7。 H2气体暴露期间氢的掺入支持气体色素过程的双注射模型，其中溶解质子。在减少WT的角色中发挥作用。在高真空中进行热处理期间，从HXWO_3膜中氢的热释放约为600 K，并伴随着膜的颜色，表明W6的降低并从表面释放了H20。氢在空气中的热释放行为与真空相同，而膜的颜色被抑制。