Thickness-dependent structure-property relationships in strained (110) SrRuO₃ Thin Films

Thickness-dependent structure-property relationships in strained SrRuO ₃ thin films on GdScO₃ (GSO) substrates are reported. The film is found to have epitaxially stabilized crystal structures that vary with the film thickness. Below 16 nm, the √2a_pc × √2a_pc × 2a_pc monoclinic structure is stabilized while above 16 nm the film has the a_pc × 2a _pc × a_pc tetragonal structure. The thickness-dependent structural changes are ascribed to the substrate-induced modification in the RuO₆ octahedral rotation pattern, which highlights the significance of the octahedral rotations for the epitaxial strain accommodation in the coherently-grown films. Close relationships between the structural and physical properties of the films are also found. The monoclinic film has the uniaxial magnetic easy axis 45° away from the [110] _GSO direction while the tetragonal film has the one that lies along the in-plane [1-10]_GSO direction. The results demonstrate that the octahedral rotations in the strained perovskite oxide thin films are a key factor for determining their structure phases and physical properties. Thickness-dependent structure-property relationships in strained SrRuO ₃ thin films are reported. The thin film changes from the monoclinic structure below 16 nm to the tetragonal structure above the thickness. The thickness-dependent structure is ascribed to the substrate-induced modification in the RuO₆ octahedral rotation pattern. Physical properties such as magnetic anisotropy are closely related to the thin-film structure.