Tuning high magnetizations in foam-like carbon-based films completely filled with α-Fe

We report an advanced chemical vapour deposition approach which yields not previously observed carbon-based foam-like films completely filled with a single phase of α-Fe. These films are found in the region of the chemical vapour deposition reactor where the temperature is relatively low (650-770 °C) and exhibit a high saturation magnetization as high as 200-220 emu/g at room temperature when small concentrations of Cl-radicals are added to the pyrolysing CVD system by mixing 0.15 ml of dichlorobenzene to ferrocene. Instead when the only ferrocene is used a lower saturation magnetization of 140-145 emu/g is found due to an amorphous arrangement of the Fe-phase in some parts of the foam. Also we show that for much higher concentration of Cl radicals (0.65 ml of dichlorobenzene mixed to ferrocene) a dramatic decrease of the quantity of crystalline α-Fe is found together with the formation of amorphous Fe and Fe_xO_x phases.