Strain-induced perpendicular magnetic anisotropy in La\(_2\)CoMnO\(_{6-\epsilon}\) thin films and its dependence with film thickness

• Published in: arXiv.org 2016-03
• Main Authors: Galceran, Regina, López-Mir, Laura, Bozzo, Bernat, Cisneros-Fernández, José, Santiso, José, Balcells, Lluis, Frontera, Carlos, Martínez, Benjamín
• Format: Article
• Language: English
• Subjects: Coercivity; Compressive properties; Crystallography; Dependence; Epitaxial growth; Ferromagnetic materials; Film thickness; Magnetic anisotropy; Oxygen content; Parameters; Shrinkage; Substrates; Tensile strain; Thin films; Unit cell
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1510.08685

Ferromagnetic insulating La\(_2\)CoMnO\(_{6-\epsilon}\) (LCMO) epitaxial thin films grown on top of SrTiO\(_3\) (001) substrates presents a strong magnetic anisotropy favoring the out of plane orientation of the magnetization with a strong anisotropy field (\(\sim 70\) kOe for film thickness of about 15 nm) and with a coercive field of about 10 kOe. The anisotropy can be tuned by modifying the oxygen content of the film which indirectly has two effects on the unit cell: i) change of the orientation of the LCMO crystallographic axis over the substrate (from c in-plane to c out-of-plane) and ii) shrinkage of the out of plane cell parameter, which implies increasing tensile strain of the films. In contrast, LCMO films grown on (LaAlO\(_3\))\(_{0.3}\)(Sr\(_2\)AlTaO\(_6\))\(_{0.7}\) and LaAlO\(_3\) substrates (with a larger out-of-plane lattice parameter and compressive stress) display in-plane magnetic anisotropy. Thus, we link the strong magnetic anisotropy observed in La\(_2\)CoMnO\(_{6-\epsilon}\) to the relation between in-plane and out-of-plane parameters and so to the film stress.