在其吸收过程中Pr2Co7D的晶体和局部结构由中子衍射确定
Kenji Iwase1, Yuhei Shitoh1, Kazuhiro Mori2
1Department of Materials Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi 316-8511, Japan.
Inorganic chemistry
|October 21, 2024
概括
中子衍射揭示了 Pr2Co7 在吸收后的结构变化. Pr2Co7D2.7采用Ce2Ni7类型的结构,而Pr2Co7D7.2则转变为具有显著格子扩张的正方形结构.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 合金 (Pr2Co7) 由于其磁性和结构性质而引起人们的兴趣.
- 的吸收可以显著改变金属间化合物的晶体结构和特性.
- 了解这些结构变化对于开发新材料至关重要.
研究的目的:
- 使用中子衍射研究Pr2Co7,Pr2Co7D2.7和Pr2Co7D7.2的晶体和局部结构.
- 确定占用地点及其对格子参数的影响.
- 分析吸收引起的结构变化.
主要方法:
- 用中子衍射来研究晶体结构.
- 瑞特维尔德精细化被用来确定结构模型和格子参数.
- 应用对分布函数 (PDF) 分析来研究局部原子排列.
主要成果:
- 发现Pr2Co7D2.7采用了Ce2Ni7类型的结构,占据了CaCu5类型和MgZn2类型的位置.
- 对于Pr2Co7D7.2.2.,观察到从Ce2Ni7类型的结构转变为正方形结构.
- 量化了显著的格子扩张,特别是在Pr2Co7D2.7的c轴上,以及Pr2Co7D7.2的近同otropic扩张.
- 在PDF分析中,Pr2Co7D7.2中发现了局部扭曲,偏离了远程结构.
结论:
- 的吸收会导致Pr2Co7.7中显著的结构变化和晶格扩张.
- 占用地点和由此产生的结构阶段取决于含量.
- 在高度减肥的Pr2Co7D7.2中存在局部扭曲,表明复杂的短距离排序.
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