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

由于它们能够探测特定核的局部环境，固态核磁共振和Mössbauer光谱学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。将获得局部结构紊乱（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方法制备的纳米晶复合氧化物中的扩散现象和动力学的定量信息。阐明机械合成纳米粒子核壳构型形成的微观机制，扩大对不同化学成分的相关纳米结构中粒子核壳内非平衡离子分布和倾斜自旋排列的理解，将具有重要意义。核光谱技术提供的短程结构信息将由宏观尺度上对机械化学制备的氧化物的行为和性质的研究来补充，目的是建立它们的纳米结构和磁性的相互作用。

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.