Nanoglassy oxides via mechanochemistry: the formation mechanism, the short-range structure, functional properties and the thermal stability

采用远离平衡的一步机械合成方法合成了LiMX2O6(M=Fe3+，Al3+，Ga3+；X=Si4+，Ge4+)新型纳米级含锂辉石化合物。由于它们能够探测特定原子核的局部环境，互补的核光谱方法，如多核核磁共振和穆斯堡尔光谱，将提供对氧化物纳米玻璃的短程结构的详细洞察。主要的焦点将集中在澄清引起机械触发形成密度增加的纳米级构建块的机制，这些构建块被机械合成材料中密度降低的界面非晶区隔开。关于纳米氧化物局部原子和电子结构的定量信息将得到对其动力学、电和磁行为的研究的补充，目的是明确解释其功能性质的基本起源。为了确定纳米玻璃的热稳定性范围，并确定它们在局部尺度上达到平衡态的松弛路径，还将研究机械合成固体对温度变化的响应。

Novel nanoglassy Li-containing pyroxene-type compounds with the composition of LiMX2O6 (M = Fe3+, Al3+, Ga3+; X = Si4+, Ge4+) will be prepared via far-from equilibrium one-step mechanosynthesis. Due to their capabilities to probe the local environment of a particular nucleus, complementary nuclear spectroscopic methods such as multi-nuclear NMR- and Mössbauer spectroscopies will provide detailed insight into the short-range structure of the oxide nanoglasses. The main focus will be given to the clarification of the mechanisms giving rise to the mechanically triggered formation of nanoglassy building blocks of enhanced density separated by interfacial amorphous regions with a reduced density in the mechanosynthesized materials. Quantitative Information on the local atomic and electronic structures of the nanoglassy oxides will be complemented by the investigation of their dynamic, electric and magnetic behavior with the aim to provide a clear-cut explanation of the fundamental origin of their functional properties. In order to determine the range of thermal stability of the nanoglasses and to identify their relaxation paths to the equilibrium state at the local scale, the response of the mechanosynthesized solids to changes in temperature will also be studied.