Coexistence of perpendicular magnetic anisotropy and ferromagnetic insulation in vertically aligned nanocomposite films

Perpendicular magnetic anisotropy and ferromagnetic insulating behavior are two key properties for the advancement of spintronic devices, yet their coexistence in a single material system remains challenging. In this work, we report the epitaxial growth of (La0.7Sr0.3MnO3)1−x:(MgO)x (x = 0, 0.1, 0.3, and 0.5) vertically aligned nanocomposite thin films on SrTiO3(001) substrates, in which both properties are simultaneously realized. The introduction of vertically aligned MgO nanopillars induces strong out-of-plane (OOP) lattice elongation in the LSMO matrix, leading to a reorientation of the magnetic easy axis from in-plane to OOP with increasing MgO content. In parallel, a transition from metallic-insulating behavior to fully insulating conduction is observed with increasing MgO concentration. This study demonstrates the dual modulation of magnetic and transport properties via vertical strain engineering, offering a powerful platform for next-generation spintronic device design.