Epitaxial Growth of NdFeAsO Thin Films by Molecular Beam Epitaxy

TL;DR

This paper reports the successful epitaxial growth of NdFeAsO thin films on GaAs substrates using molecular beam epitaxy, demonstrating high-quality phase formation with reproducibility and analyzing their electrical properties.

Contribution

First demonstration of epitaxial NdFeAsO thin films grown by MBE with detailed characterization and reproducibility.

Findings

High-quality NdFeAsO films with no impurity phases

C-axis oriented growth confirmed by XRD

Resistivity increases as temperature decreases

Abstract

Epitaxial films of NdFeAsO were grown on GaAs substrates by molecular beam epitaxy (MBE). All elements including oxygen were supplied from solid sources using Knudsen cells. The x-ray diffraction pattern of the film prepared with the optimum growth condition showed no indication of impurity phases. Only (00l) peaks were observed, indicating that NdFeAsO was grown with the c-axis perpendicular to the substrate. The window of optimum growth condition was very narrow, but the NdFeAsO phase was grown with a very good reproducibility. Despite the absence of any appreciable secondary phase, the resistivity showed an increase with decreasing temperature.