Magnetic Properties of Iron Selenide Nanocrystals Synthesized by the Thermal Decomposition

Iron selenide nanocrystals with hexagonal (H) and monoclinic (M) NiAs-like structure were synthesized via a one-pot thermal decomposition of ferrous chloride and Se powder in oleylamine. Magnetic measurements indicate that the Curie temperature of the synthesized hexagonal phase and monoclinic phase is 453 K and 340 K, respectively. The obtained magnetization sigma
_1.1
tau (300 K) for H-phase and M-phase are respectively 9.6 and 6.9 emu/g. Moreover, for the H-phase nanocrystals the spin-rotation process occurs abruptly at about 130 K, while the process does not take place in the case of M-phase.