Iron sulfide nanoparticles: preparation, structure, magnetic properties

The series of iron sulfide nanoparticles (NPs) were synthesized with the polyol mediated process which exploits high-boiling polyalcohol solvents at different boiling temperatures (T$_{B}$) what determined the NPs phase state from Fe$_3$S$_4$ to FeS. The XRD and HRTEM revealed the content of the Fe$_3$S$_4$ cubic phase to reduce linearly with the T$_{B}$ increase, and at T$_{B}=320^\circ$ C the FeS phase became predominant. Non monotonous coercivity dependence on the NPs phase state is revealed and interpreted.