Synthesis and Transfer of Freestanding Strain-Engineered Vertically Aligned Nanocomposite Thin Films

TL;DR

This paper presents a novel method for creating freestanding, strain-engineered vertically aligned nanocomposite thin films with preserved magnetic properties, enabling advanced applications in spintronics and optomagnetics.

Contribution

It introduces a SrVO3-mediated lift-off process to produce and transfer freestanding nanocomposite membranes while maintaining their structural and magnetic integrity.

Findings

Successful fabrication of freestanding CoxNi1-x nanowire arrays embedded in SrTiO3.

Preservation of magnetic properties after substrate removal.

Demonstration of potential for integration into spintronic and optomagnetic devices.

Abstract

The recent development of freestanding oxide thin films opens up exciting opportunities for the design of novel heterostructures with enhanced functionalities. Here, we explore the fabrication of membranes consisting of dense arrays of ultrathin CoxNi1-x nanowires epitaxially embedded in a SrTiO3 matrix. Through combined x-ray absorption spectroscopy, x-ray resonant magnetic scattering, x-ray diffraction and magnetooptical experiments, we show how a SrVO3-mediated lift-off process can be used to create and transfer these membranes while simultaneously preserving the structural and chemical integrity of the self-assembled, metallic CoxNi1-x nanopillars. With this approach, the large axial deformation of the embedded nanostructures is kept intact and, as a direct consequence, the magnetic properties of the nano-composite thin films remain largely unaltered after substrate removal. Our findings thus highlight a novel route for the synthesis of freestanding, strain-engineered vertically aligned heterostructures and pave the way for their future integration into spintronic and optomagnetic devices.