Heteroepitaxial growth and optoelectronic properties of layered iron oxyarsenide, LaFeAsO

Abstract

The epitaxial thin films of LaFeAsO were fabricated on MgO(001) and mixed-perovskite (La,Sr)(Al,Ta)O3(001) single-crystal substrates by pulsed laser deposition using a Nd-doped yttrium aluminum garnet second harmonic source and a 10at.% F-doped LaFeAsO disk target. Temperature dependences of the electrical resistivities showed no superconducting transition in the temperature range of 2–300K and were similar to those of undoped polycrystalline bulk samples. The transmittance spectrum exhibited a clear peak at ∼0.2eV, which is explained by ab initio calculations.