Trends in (LaMnO(3))(n)/(SrTiO(3))(m) superlattices with varying layer thicknesses

We investigate the thickness dependence of the structural, electronic, and magnetic properties of (LaMnO(3))(n)/(SrTiO(3))(m) (n, m = 2, 4, 6, 8) superlattices using density functional theory. The electronic structure turns out to be highly sensitive to the onsite Coulomb interaction. In contrast to bulk SrTiO(3), strongly distorted O octahedra are observed in the SrTiO(3) layers with a systematic off centering of the Ti atoms. The systems favour ferromagnetic spin ordering rather than the antiferromagnetic spin ordering of bulk LaMnO(3) and all show half-metallicity, while a systematic reduction of the minority spin band gaps as a function of the LaMnO(3) and SrTiO(3) layer thicknesses originates from modifications of the Ti d(xy) states.