Development of a newly designed ultraviolet Raman scattering system for in-site observation of structure at very high temperature

开发新设计的紫外拉曼散射系统，用于极高温度下的结构现场观察

• 批准号: 10555215
• 负责人: KAKIHANA Masato
• 金额: $ 7.55万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10555215/
• 关键词: Raman scattering; ultra-violet light; thermal emission; in-site observation at high temperature; zirconia; hafnia; perovskite; (1)ラマン散乱; (2)紫外光; (3)熱幅射; (4)高温その場観察; (5)ジルコニア; (6)ハフニア; (7)ペロブスカイト; 紫外; ラマン分光; 構造; 相転移; その場観察

It is of prime importance to observe change in structure of ceramics in-situ at high temperature for controlling materials properties and compositions. In the field of ceramics, since the X-ray diffraction method is most frequently used for phase identification, the technique has been extended to in-situ observation of ceramic structure at high temperature. However, X-ray diffraction techniques are not always suitable for systems like ceramics, where positions of oxygen atoms play a crucial role in determining properties and phase transformations, or for samples comprised of ultra fine powders. For this reason, it is required to develop an alternative to the X-ray diffraction technique, which enables us to carry out studies at high temperatures. To achieve this requirement, we have developed a newly designed Raman scattering system combined with an ultra-violet excitation light source. In ordinary Raman scattering experiments, conventional visible light Ar lasers have been used as excitation sources for Raman spectra. Wavelengths most frequently used for Raman scattering include the blue line at 488 nm and the green line at 515 nm. However, in case where these visible lights are used for Raman scattering experiments at high temperature, a very strong background coming from thermal emissions interfere quite severely with the observation of relatively weak Raman scattering. To overcome this serious problem, we have designed a new Raman scattering system combined with an excitation source having a wave length 363 nm, which made possible to measure Raman spectra at temperatures even higher than 1500℃. We have successfully measured Raman spectra of various high temperature materials (hafnia, zirconia, and perovskite) and clearly observed their phase transformations in situ at high temperatures. For instance, the monoclinic-to-tetragonal transformation of hafnia finished around 2080 K on heating, while the monoclinic phase appeared at 2018 K on cooling.

原位观察陶瓷材料在高温下的结构变化对控制材料性能和成分具有重要意义。在陶瓷领域，由于X射线衍射法是最常用于相鉴定的方法，该技术已扩展到高温下原位观察陶瓷结构。然而，X射线衍射技术并不总是适用于陶瓷等系统，其中氧原子的位置在确定性能和相变方面起着至关重要的作用，或者适用于由超细粉末组成的样品。因此，需要开发一种替代X射线衍射技术的方法，使我们能够在高温下进行研究。为了实现这一要求，我们开发了一种新设计的拉曼散射系统结合紫外激发光源。在普通的拉曼散射实验中，常规的可见光Ar激光器被用作拉曼光谱的激发源。最常用于拉曼散射的波长包括488 nm处的蓝线和515 nm处的绿色线。然而，在这些可见光用于高温下的拉曼散射实验的情况下，来自热发射的非常强的背景非常严重地干扰相对弱的拉曼散射的观察。为了克服这一严重问题，我们设计了一种新的拉曼散射系统，它与波长为363 nm的激发源相结合，使得在甚至高于1500℃的温度下测量拉曼光谱成为可能。我们已经成功地测量了各种高温材料（氧化铝，氧化锆和钙钛矿）的拉曼光谱，并清楚地观察到它们在高温下的相变。例如，单斜晶系到四斜晶系的转变在加热时在2080 K左右完成，而在冷却时在2018 K出现单斜晶系。

项目成果

W S. Cho, M. Kakihana: "Chracterization of si_3N_4/SiC nanocomposite by Raman scattering and XPS"Journal of Alloys and Compounds. 285. 255-259 (1999)

W S. Cho、M. Kakihana：“通过拉曼散射和 XPS 表征 si_3N_4/SiC 纳米复合材料”《合金与化合物杂志》。

W. S. Cho, M. Kakihana: "Characterization of SiィイD23ィエD2NィイD24ィエD2/SiC nanocomposite by Raman scattering and XPS"Journal of Alloys and Compounds. 285. 255-259 (1999)

W. S. Cho、M. Kakihana：“通过拉曼散射和 XPS 表征 SiD23D2N2D24D2/SiC 纳米复合材料”《合金与化合物杂志》285. 255-259 (1999)。

H.Fujimori,M.kakihana: "In situ ultraviolet Ramann study of the phase transition of hafnia up to 2085k"Journal of American Ceramic Society. (発表予定).

H.Fujimori、M.kakihana：“2085k 以下铪相变的原位紫外拉曼研究”美国陶瓷学会杂志（待出版）。

O.Yokota: "In situ measurements of the cubic-tetragoral phase transition of Zr_<1-x>Y_xO_<2-xl2> cd high tanpenitures up to ISEIK" JAERI-memo. 10・028. 254-255 (1998)

O. Yokota：“Zr_<1-x>Y_xO_<2-xl2> cd 高 tanpenitures 的立方-四方相变的原位测量，直至 ISEIK”JAERI-memo（10・028）。

H.Fujimori,M.Kakihana: "Phase transition and soft phonon modes in SrZrO_3 around 1200℃ by ultraviolet laser raman spectroscopy"Physical Review B. 61・3. 895-901 (2000)

H.Fujimori、M.Kakihana：“利用紫外激光拉曼光谱分析 1200℃ 左右 SrZrO_3 的相变和软声子模式”Physical Review B. 61・3 (2000)