High-pressure synthesis and properties of novel simple oxides with unusual stoichiometries

具有不寻常化学计量的新型简单氧化物的高压合成和性能

• 批准号: 402706186
• 负责人: Dr. Sergey V. Ovsyannikov
• 金额: --
• 依托单位: Bayerisches Forschungsinstitut für Experimentelle Geochemie und Geophysik (BGI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/402706186?language=en
• 关键词: pressure; synthesis; properties; novel; simple

Recent discoveries and studies of novel simple oxides of iron (FexOy) with hitherto unknown stoichiometries (e.g., Fe4O5, Fe5O6, Fe7O9, etc.), which can be synthesized at high-pressure high-temperature (HP-HT) conditions, showed that these oxides are of an exceptional interest for natural sciences. Alike magnetite (Fe3O4), these mixed-valent simple iron oxides present the perfect model systems to investigate the interrelations between the charge interactions and physical properties. In particular, the charge-ordering transitions of metal-insulator-type discovered in Fe3O4, Fe4O5 and Fe5O6 were found to be concurrent with extraordinary distortions in their crystal structures. The present project is dedicated to HP-HT synthesis and investigation of physical properties of novel simple oxides of three common transition metals, such as iron, titanium and manganese. We will synthesize novel mixed-valence phases of these simple oxides and investigate their electronic, optical, vibrational, mechanical, magnetic, and other properties in the wide ranges of temperatures and applied pressures. Our research will involve a variety of experimental techniques including but not limited to: single crystal X-ray diffraction, neutron diffraction, Mössbauer spectroscopy, Raman spectroscopy, Infrared and optical absorption spectroscopy, and measurements of different physical characteristics, such as: electrical resistivity, thermoelectric power, magnetic susceptibility, magnetization, dielectric constant, electric polarization, and others. This study seems to be highly important from both fundamental and applied perspectives. Results of these investigations would facilitate an understanding of physical properties of more complex strongly correlated oxides.

最近发现和研究了具有迄今未知化学计量的新型简单铁氧化物（FexOy）（例如，Fe 4 O 5、Fe 5 O 6、Fe 7 O 9等），其可以在高压高温（HP-HT）条件下合成，表明这些氧化物对自然科学具有特殊的意义。与磁铁矿（Fe 3 O 4）一样，这些混合价的简单铁氧化物为研究电荷相互作用与物理性质之间的相互关系提供了完美的模型系统。特别是，在Fe 3 O 4，Fe 4 O 5和Fe 5 O 6中发现的金属-绝缘体型的电荷有序转变被发现与它们的晶体结构中的异常畸变同时发生。本项目致力于三种常见过渡金属（如铁、钛和锰）的新型简单氧化物的HP-HT合成和物理性质的研究。我们将合成这些简单氧化物的新型混合价相，并研究它们在宽范围的温度和压力下的电子，光学，振动，机械，磁性和其他性质。我们的研究将涉及各种实验技术，包括但不限于：单晶X射线衍射，中子衍射，穆斯堡尔光谱，拉曼光谱，红外和光学吸收光谱，以及不同物理特性的测量，如：电阻率，热电功率，磁化率，磁化强度，介电常数，电极化等。从基础和应用的角度来看，这项研究似乎非常重要。这些调查的结果将有助于更复杂的强关联氧化物的物理性质的理解。