PULSED METALORGANIC CHEMICAL VAPOR DEPOSITION OF IRON OXIDES AND BISMUTH - IRON OXIDES

摘要

Deposition of thin films of iron oxides and bismuth/iron oxides on SrTiO_3 and MgO substrates was carried out in a low-pressure pulsed-metalorganic chemical vapour deposition system. For iron oxide films, we studied the effect of the oxygen partial pressure in the reactor. On SrTiO_3 substrates, γ-Fe_2O_3 phase is grown for oxygen flow from 300 to 400 sccm. On MgO substrates, the Fe_3O_4 phase grows with no oxygen in the reactor. We also studied the effect of pulse frequency, and observed that distinctive phases are grown for distinctive frequencies. The magnetic properties of the films were studied. A saturation magnetization (Ms) of 200 emu.cm~(-3) and a coercitive field (Hc) of 400 Oe were obtained for γ-Fe_2O_3 films. A saturation magnetization of 100 emu.cm~(-3) and a coercitive field of 300 Oe were obtained for Fe_3O_4 films. We also examined the effect of bismuth addition and particularly, we underlined the parameters that control the growth of BiFeO_3 phase on SrTiO_3 substrates. BiFeO_3 films exhibit a saturation magnetization of 30 emu.cm~(-3).