The in-plane magnetic anisotropy in manganite film: A novel magnetic anisotropy induced by structural anisotropy

Magnetic anisotropy plays an important role in the development of manganite-based magnetic devices. Establishing a deeper understanding of the anisotropy in manganites is useful for controlling their magnetic properties. We have studied the structure, lattice strain, and magnetic properties of La0.5Ba0.5MnO3 (LBMO-5) films with the thickness of 12 nm–96 nm, grown on the (001) SrTiO3 (STO) substrate. The LBMO-5 films are grown with high crystalline quality. The orientation relationship between the LBMO-5 film and the STO substrate [(001)f//(001)s, (010)f//(010)s, and (100)f//(100)s] exists at the film/substrate interface. With increasing the thickness of the film to 48 nm, the LBMO-5 film is fully strain relaxed. The LBMO-5 film shows the out-of-plane magnetic anisotropy (OMA) along the three mutually perpendicular crystalline axis directions. Usually, the manganite films with tetragonal distortion show both the OMA and the in-plane magnetic isotropy. However, the in-plane magnetic anisotropy (IMA) along the two mutually perpendicular in-plane directions ([010]f and [100]f) is clearly observed in LBMO-5 films. We attribute this new observation of the IMA to the in-plane structural anisotropy along the two distinct crystalline axes. Our studies provide helpful guidance for the understanding and the tuning of the IMA.