Homogeneous and Heterogeneous Mechanochemical Reactions in Spinels Studied by Mössbauer Spectroscopy and NMR

通过穆斯堡尔谱和核磁共振研究尖晶石中的均相和非均相机械化学反应

• 批准号: 14433579
• 负责人: Professor Dr. Klaus Dieter Becker
• 金额: --
• 依托单位: Institut für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/14433579?language=en
• 关键词: Homogeneous; Heterogeneous; Mechanochemical; Reactions; Spinels

Due to their capabilities to probe the local environment of a particular nucleus, solid-state nuclear magnetic resonance and Mössbauer spectroscopy will provide detailed insight into the far-from-equilibrium mechanochemical processes in spinel oxides. Quantitative information on the local structural disorder (a nonequilibrium cation distribution, a canted spin arrangement, an alteration of the nearest-neighbor configuration, a deformation of the polyhedron geometry, etc.) as well as on the diffusion phenomena and dynamics of ions in nanocrystalline complex oxides prepared by mechanochemical routes will be obtained. It will be of major importance to clarify the microscopic mechanism leading to the formation of the core–shell configuration in mechanosynthesized nanoparticles and to expand the understanding of both nonequilibrium ionic distribution and canted spin arrangement within the particle core and shell in the series of related nanostructures of various chemical compositions. Information on the short-range structure, provided by the nuclear spectroscopic techniques, will be complemented by the investigation of the behavior and properties of mechanochemically prepared oxides on a macroscopic scale with the aim to establish the interplay of their nanostructure and magnetism.

由于它们能够探测特定原子核的局部环境，固态核磁共振和穆斯堡尔谱将为尖晶石氧化物中远离平衡的机械化学过程提供详细的见解。局部结构紊乱的定量信息（非平衡阳离子分布、倾斜自旋排列、最近邻构型的改变、多面体几何形状的变形等）以及离子在机械化学法制备的纳米复合氧化物中的扩散现象和动力学。这将是非常重要的，以澄清的微观机制，导致形成的核-壳结构的机械合成纳米粒子和扩展的非平衡离子分布和倾斜的自旋排列的理解在一系列相关的纳米结构的各种化学组成的颗粒核和壳。由核光谱技术提供的短程结构信息将通过在宏观尺度上研究机械化学制备的氧化物的行为和性质来补充，目的是建立其纳米结构和磁性的相互作用。