Ordered hybrid metamaterial of La0.7Sr0.3MnO3–Au vertically aligned nanocomposites achieved on templated SrTiO3 substrate

Coupled multifunctionalities in nanocomposite thin films offer a pathway toward future integration of device applications. The oxide–metal two-phase nanocomposite thin films in a vertically aligned nanocomposite (VAN) morphology allow for unique structural control and functionality tuning toward future nanoscale devices. However, achieving in-plane ordering of the two phases remains challenging. In this work, we demonstrate an initial success of in-plane long-range ordering achieved in a new oxide–metal VAN system, La0.7Sr0.3MnO3 (LSMO)–Au, through annealed SrTiO3 (STO) substrates. The combination of plasmonic Au and ferromagnetic LSMO enables multifunctionalities, including magneto-optic coupling, hyperbolic dispersion, and tunable ferromagnetic anisotropy. Beyond this LSMO–Au VAN system demonstrated in this work, the long-range ordered two-phase structures induced by perovskite substrate surface terraces can be applied to other oxide–metal VAN systems.