Study on atomic diffusion process promoted by hydrogen absorption measured by time domain analysis of nuclear resonant X-ray scattering

核共振X射线散射时域分析测量氢吸收促进原子扩散过程研究

• 批准号: 21360019
• 负责人: OKANO Tatsuo
• 金额: $ 11.9万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21360019/
• 关键词: 放射光; 原子拡散; 鉄; 核共鳴X線散乱; 水素; 量子ビート; 時間スペクトル; 高圧; 拡散係数; 拡散の活性化エネルギー; 核共鳴X線; 鉄同位体

One of the general properties of Metal-Hydrogen system is formation of superabundant vacancies and enhancement of atomic diffusion by many orders of magnitude in some cases. Such phenomena are extensively investigated for Pd, Cu, Ni. However, experimental investigation for Fe is very few. Main object of our research is to elucidate atom diffusion mechanisms under high hydrogen pressures by using nuclear resonant forward scattering(NRFS) of X-rays combined with high pressure techniques. In the experiment、atomic diffusion in 4μm thick 57Fe foil was investigated for temperatures between RT and 1000℃under hydrogen pressures up to 2. 8GPa.Detailed analysis of experimental data is still under way. The followings are the tentative conclusions of this research project.(1) Internal magnetic field of iron foil was measured by Zeeman splitting of hyperfine states. At hydrogen pressure of 2. 8GPa, the internal field disappeared above 640℃. It was concluded that it demonstrated the lowering ofα-γstructural phase transition temperature by hydrogen absorption.(2) It was observe at temperature 960℃that significant change in time spectrum of nuclear resonant forward X-ray scattering took place. We concluded that this abrupt change was due to the lowering of melting point of Fe foil with abundant hydrogen absorption.(3) No enhancement of atomic diffusion by hydrogen absorption was observed for the present experimental condition : Temperatures from RT and 1000℃and hydrogen pressure 2. 8GPa. Main reason for this absence of hydrogen effect is vacancy diffusion mechanism was surpassed by much faster diffusion process such as surface diffusion or subsurface diffusion. It illustrates the importance of surface phenomena in atomic transportation in polycrystalline materials.

金属-氢系统的一般性质之一是形成过多的空位，在某些情况下原子扩散增强了许多个数量级。这种现象在Pd、Cu、Ni中得到了广泛的研究。然而，对铁的实验研究很少。我们研究的主要目的是利用X射线的核共振前向散射(NRFS)结合高压技术来阐明高氢压力下的原子扩散机制。在实验中，研究了、原子在4μm厚的57Fe箔中的扩散，温度范围为RT至1000℃，氢气压力高达2.8 Gp。实验数据的详细分析仍在进行中。本研究的初步结论如下：(1)利用超精细态的塞曼分裂测量了铁箔的内部磁场。当氢压为2.8℃时，内场在640 Gpa以上消失。结果表明，吸氢降低了α-γ的结构相变温度。(2)在960℃的温度下，观察到核共振正向X射线散射的时间谱发生了显著的变化。我们的结论是，这一突变是由于吸氢丰富的铁箔熔点降低所致。(3)在本实验条件下，未观察到在RT和1000℃温度和氢气压力2.8 GPa时通过吸氢增强原子扩散。没有氢效应的主要原因是空位扩散机制被更快的扩散过程所超越，如表面扩散或亚表面扩散。它说明了表面现象在多晶材料中原子输运中的重要性。

项目成果

核共鳴X線前方散乱を用いた高水素圧下のFeの原子拡散と磁性の研究

利用核共振X射线前向散射研究高氢压力下Fe的原子扩散和磁性

• 发表时间: 2012
• 作者: 笠井秀隆;河内泰三;深井有;張小威;岸本俊二;亀卦川卓美;依田芳卓;大谷栄治;松本益明;岡野達雄
• 通讯作者: 岡野達雄

Surface magnetic canting of ion films

离子膜的表面磁倾斜

• 发表时间: 2011
• 期刊: Phys. Rev. B
• 作者: T. Kawauchi;K. Fukutani;M. Matsumoto;K. Oda;T. Okano;X. W. Zhang;Y. Yoda
• 通讯作者: Y. Yoda

核共鳴X線前方散乱を用いた高水素圧力下のFeの原子拡散と磁性の研究

利用核共振X射线前向散射研究高氢压力下Fe的原子扩散和磁性

• 发表时间: 2012
• 作者: 西尾剛;楊士波;三宅秀人;平松和政;平本昌宏;Masanori Ozaki;笠井秀隆,河内泰三,深井有,張小威,岸本俊二,亀掛川卓美,依田芳卓,大谷栄治,松本益明,岡野達雄
• 通讯作者: 笠井秀隆,河内泰三,深井有,張小威,岸本俊二,亀掛川卓美,依田芳卓,大谷栄治,松本益明,岡野達雄

核共鳴X線散乱時間スペクトルによる水素誘起原子拡散の研究II

利用核共振X射线散射时间谱研究氢诱导原子扩散II

• 发表时间: 2009
• 作者: Hirokazu Fukidome;Masato Kotsugi;Yusuke Kawai;Takuo Ohkouchi;Thomas Seyller;Karsten Horn;Hiroyuki Handa;Ryota Takahashi;Kei Imaizumi;Yoshiharu Enta;Maki Suemitsu;Toyohiko Kinoshita;Yoshio Watanabe;石川正司;藪修平;Yukio Hasegawa;笠井秀隆
• 通讯作者: 笠井秀隆

Application of Nuclear Resonant X-ray Forward Scattering to the study of Diffusion of Iron Atoms under Hydrogen Pressure of GPa range

应用核共振X射线前向散射研究GPa范围氢压下铁原子的扩散

• 发表时间: 2011
• 作者: K. Kasai;T. Kawauchi;Y. Fukai;X. W. Zhang;S. Kishimoto;T. Kikegawa;Y. Yoda;E. Ohtani;T. Okano
• 通讯作者: T. Okano