Magnetic anisotropy and magnetic textures in La^sub 1-x^Sr^sub x^MnO^sub 3^ controlled by annealing

Here, we report the effects of annealing treatments on magnetic textures, such as the formation of magnetic stripe domains and magnetic bubbles, in La0.825Sr0.175MnO3 (LSMO). Magnetization measurements suggest that the orientation of the easy axis, which was oriented along the [1 0 3]C direction in the as-grown sample, shifted to the [0 0 1]C direction after an annealing treatment was applied at 1273 K. Lorentz microscopy observations revealed that 180° magnetic domains with in-plane magnetization were formed in an as-grown sample in the absence of a magnetic field and that these domains were transformed into isolated elliptical magnetic domains when a magnetic field was applied along the [0 0 1]C axis. Conversely, in annealed samples, the magnetic stripe domains magnetized perpendicular to the thin film were formed in a zero magnetic field and transformed into magnetic bubbles with circularly rotating spins. These results suggest that annealing induces a change in the magnetic anisotropy from the [1 0 3]C direction to the [0 0 1]C direction. Thus, the spatial configuration of the spins in the magnetic textures of LSMO can be controlled by annealing.