Strain Effects on the Growth of La0.7Sr0.3MnO3 (LSMO)-NiO Nanocomposite Thin Films via Substrate Control.

Abstract

Oxide-oxide-based vertically aligned nanocomposites (VANs) have demonstrated a new material platform for enhanced and/or combined functionalities because of their unique vertical geometry and strain coupling. Various factors contribute to the growth of VANs, including deposition parameters, phase composition, phase ratios, crystallography, etc. In this work, substrate strain effects are explored through growing a two-phase oxide-oxide La0.7Sr0.3MnO3 (LSMO):NiO system, combining antiferromagnetic NiO and ferromagnetic LSMO, on various substrates with different lattice parameters. The X-ray diffraction (XRD), transmission electron microscopy (TEM), and magnetic property measurements all suggest that substrate strain plays a critical role in the epitaxial growth of a VAN structure and their two-phase separation, and thus results in different physical properties. This work sheds light on the fundamental nucleation and growth mechanisms of the two-phase VAN systems and the effects of substrate strain on the overall orientation and growth quality of the VAN films.