Anisotropy-driven interfacial magnetism in Ru-deficient SrRuO${}_3$ thin films

Abstract

While stoichiometric SrRuO${}_3$ (SRO) is a metallic itinerant ferromagnet with relatively homogeneous magnetization, Ru deficiency provides a powerful route to alter its electronic transport and depth-dependent magnetic properties. Ru-deficient SRO thin films grown by radio-frequency high oxygen pressure sputtering were investigated using a combination of X-ray reflectivity, polarized neutron reflectometry, off-specular neutron scattering, scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy, electrical transport, and magnetometry. Structural and compositional analyses reveal that Ru deficiency is intrinsic to the films, with an enhanced deficiency at the interfaces. As a result, coherent electronic transport is suppressed and the saturation magnetization is reduced, while the Curie temperature remains largely unaffected, placing Ru-deficient SRO in a regime consistent with ferromagnetic insulator-like behavior. Depth- and lateral-resolved magnetic measurements further show that the interfacial regions remain ferromagnetic but exhibit enhanced perpendicular magnetic anisotropy, which constrains the local magnetization to remain predominantly out-of-plane and strongly reduces its in-plane projection. Our results establish Ru deficiency as a key control parameter governing transport, magnetization, and anisotropy in SRO thin films and highlight defect and interface engineering as powerful routes to tailor interfacial magnetism in correlated oxide heterostructures.

41 pages, 14 figures (including Supplementary Material). Submitted to APL Materials

References in corpus (15)

• Critical thickness for itinerant ferromagnetism in ultrathin films of SrRuO${}_3$
• Weyl fermions and the anomalous Hall effect in metallic ferromagnets
• Quantum transport evidence of Weyl fermions in an epitaxial ferromagnetic oxide
• Dependence of electronic structure of SrRuO3 and the degree of correlation on cation off-stoichiometry
• Observation of Spin-glass-like Behavior in SrRuO3 Epitaxial Thin Films
• Sign-tunable anomalous Hall effect induced by two-dimensional symmetry-protected nodal structures in ferromagnetic perovskite oxide thin films
• Materials challenges for SrRuO3: from conventional to quantum electronics
• Structural and transport properties of highly Ru-deficient SrRu0.7O3 thin films prepared by molecular beam epitaxy: comparison with stoichiometric SrRuO3
• The origin of insulating and non-ferromagnetic SrRuO3 monolayers
• Magnetization-density distribution in the metallic ferromagnet SrRuO3 determined by polarized neutron diffraction
• Magnetic Dead Layers in La${}_{0.7}$Sr${}_{0.3}$MnO${}_3$ Revisited
• X-ray study of structural domains in the near-surface region of SrTiO3-substrates with Y0.6Pr0.4Ba2Cu3O7$ / La2/3Ca1/3MnO3 superlattices grown on top
• Detection of the Chiral Spin Structure in Ferromagnetic SrRuO${}_3$ Thin Film
• Single-layer spin-orbit-torque magnetization switching due to spin Berry curvature generated by minute spontaneous atomic displacement in a Weyl oxide
• Magnetic domain wall motion in SrRuO${}_3$ thin films