Deposition of iron sulfide nanocrystals from single source precursors

Symmetrical and unsymmetrical dithiocarbamato complexes of iron(III) with the general formula [Fe(S2CNRR′)3] where R = Et, R′ = iPr (1); R,R′ = Hex (2); R = Me, R′ = Et (3); and R,R′ = Et (4) have been used as single source precursors to synthesize iron sulfide nanocrystals by thermolysis in oleylamine, hexadecyleamine and octadecene at different temperatures. The nanocrystals obtained were studied by p-XRD and TEM and magnetic measurements. Nanocrystals of iron sulfide with greigite, pyrrhotite and mixed phase were grown at different thermolysis temperatures from each precursor. The precursors with shorter alkyl chain length required higher temperature to give the product. Symmetrical alkyl groups with longer chain alkyl groups gave pure greigite phase at lower thermolysis temperature of 170 °C but a mixture of greigite and pyrrhotite at higher temperatures. The unsymmetrical alkyl groups gave mixed phase (greigite and pyrrhotite) iron sulfide nanocrystals at all temperatures.