Molecular Ferroelectrics

铁电材料是一种可以通过外部电场转换的永久极化的材料。它们在电容器、铁电存储器、场效应晶体管以及通过相关的压电效应在定位器和换能器中有许多应用。实际使用的铁电材料大多是以含重金属的无机氧化物BaTiO_3、PbTi_(1-x)Zr_xO_3为基料，具有加工温度高、潜在毒性大等缺点。这个项目将探索我们团队开发的方法，以尝试和识别新的分子铁电材料，从而避免这些问题。特别是，我们开发了自动对称性搜索方法，使我们能够挖掘100万个已知的晶体结构，以识别可能显示铁电性的材料。从这一数据搜索中最有希望的候选材料将被合成，并通过各种实验方法研究它们的性质。分子铁电材料的潜在优势包括易于合成和加工、低毒性以及制造与有机电子兼容的柔性材料的可能性。学生将接受结晶学(单晶和粉末)、计算方法、材料合成和介电性能测量方面的培训。

Ferroelectrics are materials which display a permanent polarisation that can be switched by an external electric field. They find a number of applications in devices such as capacitors, ferroelectric memories, in field effect transistors and, via the related piezoelectric effect, in positioners and transducers. The majority of ferrelectrics used practically are based on heavy-metal containing inorganic oxides such as BaTiO3, PbTi1-xZrxO3, which have drawbacks such as high processing temperatures and potential toxicity. This project will explore methods that our group has developed to try and identify new molecular ferroelectrics which would avoid these issues. In particular we have developed automated symmetry-searching methods allowing us to mine through the >1,000,000 known crystal structures to identify materials that might display ferroelectricity. The most promising candidate materials from this data searching will be synthesised and their properties studied by a variety of experimental methods. The potential advantages of molecular ferroelectrics include their ease of synthesis and processing, low toxicity and the possibility of producing flexible materials compatible with organic electronics. The student will receive training in crystallography (both single crystal and powder), computational methods, materials synthesis, and dielectric property measurements.