Mechanochemistry of Oxide and Fluoride Nonequilibrium Phases: Mechanosynthesis, Solid State Kinetics and Spectroscopic Properties

氧化物和氟化物非平衡相的力化学：力合成、固态动力学和光谱性质

• 批准号: 142911196
• 负责人: Professor Dr. Paul Heitjans
• 金额: --
• 依托单位: Institut für Physikalische Chemie und Elektrochemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/142911196?language=en
• 关键词: Mechanochemistry; Oxide; Fluoride; Nonequilibrium; Phases

The project deals with the directed mechanochemical synthesis and structural characterization of new crystalline oxide and fluoride non-equilibrium phases. While in the first period mainly systems crystallizing with the perovskite, olivine, garnet, fluorite, and spinel structure were investigated, in the second period, the research will be extended to more complex materials such as (i) oxides with the mullite-type structure with general composition Bi2X4O9/10 (X = Ga3+, Fe3+, Al3+, Mn3+, Mn4+), (ii) the pyroxene-type compounds, e. g., Li-containing pyroxenes LiYSi2O6 (Y = Fe3+, Al3+, Cr3+), and (iii) the Li2ZSiO4 family of oxides (Z = Fe2+, Mn2+, Co2+, Ni2+). Also other fluoride systems like BaSnF4, BaMgF4, and metastable composites based on SnF2 will be investigated. Complex problems regarding the metastable structural configurations in several systems investigated in the first period will be processed in cooperation with theoretically-oriented groups.The main focus will be given to the investigation of the mechanisms and kinetics of the formation of metastable compounds involving studies concerning their thermal stability, especially their local atomic and electronic structures. Primarily, complementary nuclear methods such as NMR- and Mössbauer spectroscopy will be used, which allow to follow the relaxation paths of the as-prepared phases to the equilibrium state and associated kinetics at the local scale. Besides the determination of the local structure of the non-equilibrium phases the investigation of the dynamic, electric and magnetic properties is the second priority of the project. The project shall contribute to an understanding of the structure-forming factors which govern the formation mechanisms of the mechanosynthesized non-equilibrium phases, in order to manipulate them in a directed way for the synthesis of new functional materials.

该项目涉及新的结晶氧化物和氟化物非平衡相的定向机械化学合成和结构表征。第一阶段主要研究钙钛矿、橄榄石、石榴石、萤石和尖晶石结构的结晶体系，第二阶段的研究将扩展到更复杂的材料，如（i）具有莫来石型结构的氧化物，其一般组成为Bi 2 X 4 O 9/10（X = Ga 3+，Fe 3+，Al 3+，Mn 3+，Mn 4+），（ii）辉石型化合物，如Al 2 O3。例如，在一个实施例中，含Li的辉石LiYSi 2 O 6（Y = Fe 3+，Al 3+，Cr 3+），和（iii）Li 2 ZSiO 4族氧化物（Z = Fe 2+，Mn 2+，Co 2+，Ni 2+）。还将研究其他氟化物系统，如BaSnF 4、BaMgF 4和基于SnF 2的亚稳复合材料。第一阶段研究的几个系统的亚稳结构构型的复杂问题将与理论导向的小组合作处理。主要重点将是亚稳化合物形成的机制和动力学的研究，包括对它们的热稳定性的研究，特别是它们的局部原子和电子结构。首先，补充核方法，如NMR和穆斯堡尔谱将被使用，它允许遵循的松弛路径的准备阶段的平衡状态和相关的动力学在当地的规模。除了确定非平衡相的局部结构外，动力学、电学和磁学性质的研究是该项目的第二优先事项。该项目将有助于理解控制机械合成非平衡相形成机制的结构形成因素，以便以直接的方式操纵它们以合成新的功能材料。