Substrate-induced magnetic anisotropy in La0.7Sr0.3MnO3 epitaxial thin films grown onto (110) and (1 8) SrTiO3 substrates

We show a detailed magneto-optical Kerr study at room temperature of well characterized epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown onto (110) and (11̄8) SrTiO3 substrates. The films present a well-defined uniaxial (two-fold) magnetic anisotropy ascribed to substrate-induced anisotropy. In particular, the in-plane uniaxial anisotropy in the(110)-oriented LSMO films originates from the existence of elongated in-plane [001]-oriented structures. Similar elongated structures, parallel to the [110] crystallographic direction, are found for LSMO films grown on (11̄8) STO surfaces. In all films, such a uniaxial magnetic anisotropy is characterized by an easy axis lying along the elongated structures. Furthermore, the vectorial-resolved hysteresis loops as a function of the in-plane applied field direction are interpreted in terms of rotation and propagation and nucleation of magnetic domains processes. Our results demonstrate the tailoring of magnetic anisotropy by exploiting the substrate-induced anisotropy in epitaxial thin films.