Substrate orientation-induced epitaxial growth of face centered cubic Mo2C superconductive thin film

Abstract

In this study, we demonstrate the crystal structure-controlled growth of superconductive Mo₂C thin films on a sapphire(0001) substrate in the pulsed-laser deposition. Detailed characterizations indicate that the thin film grown at 700 °C adopts the face centered cubic structure with the preferred orientation of the 〈111〉 direction. It was also demonstrated that the sapphire substrate and face centered cubic structured Mo₂C thin film have the orientation relationship of {0006}sapphire//{111}Mo₂C and [010]sapphire//[10] Mo₂C due to a small in-plane lattice mismatch between their corresponding lattice spacing perpendicular to the {111} atomic plane of the Mo₂C thin film. Electrical transport measurements show that the Mo₂C thin films exhibit superconducting characteristics. This study provides a practical approach to controlling the crystal structure of superconductive Mo₂C thin films through the optimization of substrate orientation.