Pressure-dependent behaviour of an incommensurately modulated polar helical texture of copper-substituted bismuth manganite

A recently high-pressure-synthesised BiCu0.1Mn6.9O12 (Science 369 (2020) 680) is the first known bulk material with electric dipoles spontaneously ordered into an incommensurate helix. Moreover, the chiral dipole texture couples to an improper electrical polarization offering a unique opportunity to control the chiral domains and their associated optical activity by an applied electric field at room temperature. To exploit this discovery as well as to develop processing units based on compressively-strained epitaxial films of this material, the data on pressure-dependent behaviour are needed. We propose to obtain the detailed structural data in the pressure range between ambient pressure and about 9 GPa, in which the changes in both the fundamental diffraction reflections and the satellite reflections resulted from the modulation were observed in the preliminary experiment.

近期通过高压合成的BiCu0.1Mn6.9O12（Science 369 (2020) 680）是已知首个电偶极子自发排列成非公度螺旋结构的块体材料。此外，其手性偶极织构与非本征电极化耦合，为室温下通过外电场调控手性畴及其相关光学活性提供了独特契机。为利用这一发现并开发基于该材料压应变外延薄膜的处理单元，需获取其压力依赖行为的数据。我们计划在常压至约9 GPa的压力范围内获取详细结构数据，预实验已在此区间观测到由调制引起的基衍射峰及卫星峰变化。