Investigation of Formation, Stability, Structure and Hydrogen Storage Properties of Ti-Quasicrystals and Related Crystalline Phases

钛准晶及相关晶相的形成、稳定性、结构和储氢性能研究

• 批准号: 9705202
• 负责人: Kenneth Kelton
• 金额: $ 38.01万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9705202&HistoricalAwards=false
• 关键词: Investigation; Formation; Stability; Structure; Hydrogen

9705202 Kelton The atomic structures of titanium-based quasicrystals and related phases, the formability of the quasicrystal and crystal approximants, the role of impurities in phase formation, and the nature of the phase transitions connecting the quasicrystal and the crystal approximants, are as yet poorly understood. Pursuing successes under the past grant period, these points are explored in titanium and zirconium-based quasicrystals and related crystal phases. Subjects include: (1) the investigation of the role of interstitial impurities on icosahedral phase formation; (2) the hydrogenation characteristics of quasicrystals, related crystalline and amorphous phases, and the hydrogen/quasicrystal phase diagram and pressure/composition isotherms; (3) X-ray and neutron diffraction to determine the atomic decoration of stable crystal approximants in TiZrTM alloys; (4) investigations of the sequence of phase formation in TiCrSiO, TiZrNi, and TiZrFe alloys; and (5) the nature of the phase transitions between the stable icosahedral-phase and the rational approximant phases in TiZrNi alloys. Several collaborations are underway, including studies of phase formation aided by drop-tube experiments in collaboration with Cambridge University, UK; the stabilizing role of impurities by magnetic susceptibility measurements in collaboration with scientists at Washington University; neutron scattering studies of hydrogenated (and deuterated) quasicrystals in collaboration with Missouri University Research Reactor (MURR), and Saclay, France; NMR studies of samples with Knox College, IL. The elastic neutron scattering and NMR studies lead to a better understanding of the distribution, symmetry and chemistry of the hydrogen containing sites in the TiZrNi quasicrystals. These data will be used to refine quasicrystal models constructed from determined structures for the crystal approximant phases. Inelastic neutron and NMR studies allow estimates to be made to hydrogen diffusion rates in the quasicrystal. %%% This research provides fundamental knowledge related to the potential for quasicrystal alloys to function as hydrogen storage materials. ***

9705202 KELTON基于钛的准晶体和相关相的原子结构，准晶体和晶体近似物的形成性，杂质在相形成中的作用以及连接准晶体和晶体近似值的相变的性质，尚有理解。 在过去的赠款期间追求成功时，这些观点是在钛和基于锆的准晶体和相关晶体阶段探索的。 受试者包括：（1）研究间质杂质在二十面体相形成中的作用； （2）准晶体，相关晶体和无定形相的氢化特性，以及氢/准晶相图和压力/组成等温度； （3）X射线和中子衍射，以确定TIZRTM合金中稳定晶体近似值的原子装饰； （4）对TICRSIO，TIZRNI和TIZRFE合金中相形成序列的研究； （5）稳定的二十面体相和tizrni合金中有理近似相之间的相变的性质。 正在进行几项合作，包括与英国剑桥大学合作的Drop-Tube实验协助的相结合研究； 与华盛顿大学的科学家合作，通过磁化率测量的杂质稳定作用；与密苏里大学研究反应堆（MURR）和法国Saclay合作的氢化（和氘化）准晶体的中子散射研究； NMR对伊利诺伊州诺克斯学院的样品研究。 弹性中子散射和NMR研究导致对tizrni准晶体中含有氢的分布，对称性和化学的分布，对称性和化学的理解。 这些数据将用于完善由晶体近似相确定的结构构建的准晶模型。 非弹性中子和NMR研究允许对准晶体中的氢扩散率进行估计。 %%％这项研究提供了与准晶合金作为氢存材料起作用的潜力有关的基本知识。 ***