Growth Process And Magnetic Properties Of Alpha-Fese Nanostructures

Growth process and magnetic properties of PbO-type alpha-FexSe nanostructures with shape changing from nanocacti to nanopetals and then to nanosheets are investigated. With iron acetylacetonate [Fe(acac)(3)] and Se powder as raw materials, the diffusion process of Fe atoms dominates the synthesis of alpha-FexSe nanocacti following phase transitions from FeSe2 to Fe3Se4 and finally to alpha-FexSe. When a mixed solution containing Se precursor and Fe(acac)(3) was used as the raw material, the formation of FeSe2 and Fe3Se4 can be avoided and, bended alpha-FexSe nanopetals can be prepared at 345 degrees C, which became flat nanosheets with a [001] preferred orientation as extending the reaction time from 1 to 4 h. No superconducting transition occurs in the alpha-FexSe (0.84 <= x <= 1.05) nanostructures due to composition heterogeneity or size effect. Magnetic measurements indicate that an antiferromagnetic component with a Neel point at about 45 K dominates the magnetic properties of the alpha-Fe0.87Se nanosheets. (C) 2014 AIP Publishing LLC.