Deciphering ferroelectric distortions of PbCuTe2O6 below 1 K

The investigation of frustrated magnetism with the search for materials realising the quantum spin liquid state is a current active science area. Another active research topic is the study of ferroelectricity in materials realising spontaneous electric polarisation. In this proposal, we aim to investigate the compound PbCuTe2O6 which combines both properties. While the frustrated magnetic interactions in this material lead to a suppression of long-range magnetic order, the ferroelectricity which onsets at low temperatures is accompanied by a structural distortion from cubic to non-cubic symmetry. Conventional neutron diffraction is unable to resolve the changes that occur at the transition indicating that the distortion is very subtle. For this reason, we propose to study changes in the neutron pair distribution function around the transition using the Polaris instrument. As well as providing information about the ferroelectric state these results would also give insights into whether the magnetic interactions are influenced by the transition.