Improved multiferroic behavior in [111]-oriented BiFeO3/BiAlO3 superlattice

Abstract

We report a systematic study on the structural, electronic, magnetic, and ferroelectric properties of [111]-oriented BiFeO3/BiAlO3 (BFO/BAO) superlattice using density-functional calculations. It is found that the Fe-O-Fe superexchange interactions in BFO/BAO superlattice are greatly suppressed by the inserted BAO layers, with the antiferromagnetic-ferromagnetic transition energy decreasing from around 280 meV per BFO formula unit (five atoms) to 11.6 meV per BFO/BAO formula unit (ten atoms). The tensile strain can further decrease this energy, making the magnetic transition more plausible. In addition, we find that BFO/BAO superlattice preserves the large ferroelectric polarization as well as energy gap of bulk BFO. Therefore, BAO may be a good candidate for constructing the BFO-based superlattice with improved multiferroicity.

Enhancement of orbital ordering and spin polarization by controlling the dimensionality of the octahedra network

“…As indicated from the structure analysis, in the 0D structure, the RuO 6 octahedra are isolated by TiO 6 . The localized feature can be noticed in the partial DOS plotted in Figure 5c: Three localized peaks correspond to the van-Hove singularity of the truncated d xy,yz,zx orbitals, respectively.…”

“…6,7 The superexchange interaction strength of BiFeO 3 can be weakened by using a (111)-oriented substrate. 6 Also, the octahedra tilt pattern for NdNiO 3 can be changed by growth on a (111)-oriented LaAlO 3 substrate, which leads to a noncentrosymmetric metallic phase. 7 Therefore, choosing the correct substrate orientation is one of the key issues in material design.…”

Ab initio studies on phonon, dielectric, and piezoelectric responses in perovskite‐like bismuth aluminate

“…et al investigated structural parameters and elastic properties of BiAlO 3 with hexagonal phase and proved its mechanical stability. In order to improve the multiferroic behavior, Ding et al studied BiFeO 3 /BiAlO 3 superlattice using first principles method. So far, the theoretical study of BiAlO 3 has mainly focused on electronic structure and mechanical properties.…”