One-Step Atmospheric Pressure Synthesis of the Ground State of Fe Based LaFeAsO1− δ .

We report an easy and versatile one-step synthesis route for a newly discovered Fe based LaFeAsO_{1− δ} compound with 0.0≤ δ≤0.15. Instead of widely used high-pressure-high-temperature ( HPHT) synthesis, we applied the normal atmosphere solid-state reaction route. The stoichiometric mixtures of Fe, La₂O_3, La, and As in ratio LaFeAsO_{1− δ} with 0.0≤ δ≤0.15 are sealed in an evacuated quartz tube and further heated at 500, 850, and 1,100 °C in Ar for 12, 12, and 33 hours, respectively, in a single step. The resulting compounds are single phase LaFeAsO crystallized in tetragonal P4/ nmm structure. These samples showed the ground state spin density wave ( SDW) like metallic behavior below around 150 K. In conclusion, the ground state (non-superconducting) of newly discovered Fe based superconductor is synthesized via an easy one-step solid-state reaction route. [ABSTRACT FROM AUTHOR]