Magnetic Anisotropy Induced by Orbital Occupation States in La_0.67Sr_0.33MnO_3 Films

Interface engineering is an effective and feasible method to regulate the magnetic anisotropy of films by altering interfacial states between films. Using the technique of pulsed laser deposition, we prepared La_0.67Sr_0.33MnO_3 (LSMO) and La_0.67Sr_0.33MnO_3/SrCoO_2.5 (LSMO/SCO) films on (110)-oriented La_0.3Sr_0.7Al_0.65Ta_0.35O_3 substrates. By covering the SCO film above the LSMO film, we transformed the easy magnetization axis of LSMO from the 001 axis to the 1\bar10 axis in the film plane. Based on statistical analyses, we find that the corresponding Mn–Mn ionic distances are different in the two types of LSMO films, causing different distortions of Mn–O octahedron in LSMO. In addition, it also induces diverse electronic occupation states in Mn^3+ ions. The e_\rm g electron of Mn^3+ occupies 3z^2-r^2 and x^2-y^2 orbitals in the LSMO and LSMO/SCO, respectively. We conclude that the electronic spin reorientation leads to the transformation of the easy magnetization axis in the LSMO films.