Ca Solubility in a BiFeO-Based System with a Secondary BiO Phase on a Nanoscale.

In BiFeO (BFO), BiO (BO) is a known secondary phase, which can appear under certain growth conditions. However, BO is not just an unwanted parasitic phase but can be used to create the super-tetragonal BFO phase in films on substrates, which would otherwise grow in the regular rhombohedral phase (R-phase). The super-tetragonal BFO phase has the advantage of a much larger ferroelectric polarization of 130-150 μC/cm, which is around 1.