Heteroepitaxial growth and optoelectronic properties of layered iron oxyarsenide, LaFeAsO

The epitaxial thin films of LaFeAsO were fabricated on MgO(001) and mixed-perovskite (La,Sr)(Al,Ta)O-3(001) single-crystal substrates by pulsed laser deposition using a Nd-doped yttrium aluminum garnet second harmonic source and a 10 at. % F-doped LaFeAsO disk target. Temperature dependences of the electrical resistivities showed no superconducting transition in the temperature range of 2-300 K and were similar to those of undoped polycrystalline bulk samples. The transmittance spectrum exhibited a clear peak at similar to 0.2 eV, which is explained by ab initio calculations. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2996591]