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 LaFeAsO1−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, La2O3, La, and As in ratio LaFeAsO1−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.