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.