Characterization of iron and its nitride nanoparticies prepared by CVC process without using a chiller

摘要

Iron and its nitride (ε-Fe_3N) nanoparticies were fabricated by the CVC using Fe(CO)_5 precursor without the aid of LN_2 chiller. The iron particles synthesized at 400℃ were a mixture of amorphous and crystalline α-Fe. Fully crystallized iron particles were then obtained above 600℃. Iron-nitride particles that were easily formed at 500℃ at 1 atm., however, were not fully developed in vacuum unless the reaction temperature reached 850℃. Nevertheless, the work chamber needed to be maintained in vacuum to obtain finer iron-nitride particles. The synthesized particles possessing the core-shell type structure were all nearly spherical and enclosed with Fe_3O_4 or Fe_3O_4related amorphous layer. The iron nanoparticies (～20 nm) synthesized at 600℃ at 760 torr exhibited _iH_c ～ 1.0 kOe and M_s ～ 170 emu/g, whereas the iron-nitride particles (～20 nm) synthesized at 850℃ at 0.01 torr exhibited _iH_c ～ 0.45 kOe and M_s ～ 115 emu/g.