Enhancement of ferroelectric polarization in layered BaZrO3/BaTiO3 superlattices

The influence of stacking periodicity on the ferroelectric properties of layered (BaZrO3)m/(BaTiO3)n (BZO/BTO) superlattices is investigated by first-principles calculations. It is found that the presence of one unit cell thick BZO layer can strongly enhance the macroscopic polarization of the BZO/BTO superlattice. The stacking periodicity of 1/2, 1/3, and 1/4 (m/n) exhibits the polarization values of ∼38, 41 and 40 μC/cm2, respectively, which are much larger than that of bulk BTO (27 μC/cm2). In addition, a polarization enhancement can also be achieved in BZO/BTO superlattices by keeping the number of ferroelectric BTO layers same or more than the dielectric BZO layers. This BZO enhanced polarization in lead-free ferroelectric superlattice will be promising for the future application and stimulate further experimental investigations.