空位介导的NiAs-Ni2类型中的金属间相:Ni1+δ(In/Sb)
Sandip Kumar Kuila1, Sven Lidin1,2, Partha Pratim Jana1
1Department of Chemistry, IIT Kharagpur, Kharagpur 721302, India.
Inorganic chemistry
|March 5, 2026
概括
这项研究合成和分析了-锡和-/化合物,揭示了多余的原子如何影响晶体结构的演变和排序. 结果详细介绍了复杂的模块化结构及其与占用和空位障碍的关系.
科学领域:
- 固态化学和材料科学 固态化学和材料科学
- 结晶学和结构分析.
- 计算材料科学.计算材料科学.
背景情况:
- NiAs型结构及其变体在金属间化合物中很常见.
- 了解非固态度 (过量原子) 对晶体结构的影响对于材料设计至关重要.
- 之前的研究已经探索了相关的-锡和-/系统.
研究的目的:
- 合成和表征Ni1+δSn和Ni1+δ(In/Sb) 化合物,其含量不同 (δ).
- 阐明晶体结构的演变,包括无序,不相称调制和有序的超结构.
- 调查过多的原子和空位障碍在确定结构结果中的作用.
主要方法:
- 合成Ni1+δSn (δ = 0.2,0.4) 和Ni1+δ (δ = 0.1-0.5) 的合金.
- 进行X射线衍射研究以确定晶体结构.
- 使用 (3+1) D超空间形式主义对不相称的调制结构进行建模.
- 密度函数理论 (DFT) 的计算,以合理化空位障碍.
主要成果:
- 在Ni1+δ(In/Sb) 中的过量原子占据了间隙位置,导致结构从无序过渡到有序的超结构.
- 化合物表现出NiAs/Ni2 在类型结构中,观察到中间安排和不相称的调制.
- 特定的相结晶为具有调制向量的正方体超空间群 (Cmcm),而其他相采用三元Ni3Sn2类型结构.
- 结构性结果是由部分占用和空置障碍所决定的,这是DFT解释的.
结论:
- Ni1+δSn和Ni1+δ(In/Sb) 的晶体结构对固态度和间位点占用非常敏感.
- 一个复杂的相场演变,其特点是无序的,不相称调制的,相称有序的 (锁定) 结构.
- DFT计算提供了关于特定原子排列和空位分布的能量优势的见解.
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