Room-Temperature Chemical Synthesis of PbO-Type FeSe Superconducting Nanoparticles

A novel room-temperature chemical synthesis technique for PbO-type FeSe superconducting nanocrystals was developed. Since no heat treatment was involved during the reaction process, the formation of non-superconducting hexagonal δ -FeSe phase has been effectively avoided and high purity of superconducting phase was guaranteed, which were proved by both X-ray diffractometer (XRD) and high-resolution transmission electron microscope (HRTEM). FeSe nanoparticles with the critical temperature, T c of ∼ 8.9 K were obtained, which implied the effectiveness of this synthesis method. The influences of pH values on the morphology of FeSe nanoparticles and the reaction mechanisms were systematically analyzed. With the increase of pH values, the particle size decreased obviously. The reaction mechanisms with different pH values were also discussed based on the observed experimental phenomena and calculated standard electrode potentials.