Enhanced magnetization in unusual carbon-nanotube/carbon-foam cm-scale hybrid-buckypaper films with high α-Fe filling-ratio

We report the synthesis of novel and unusual α-Fe-filled carbon nanotube (CNT)/carbon foam (CFM) hybrid-buckypaper films via pyrolysis of ferrocene/dichlorobenzene mixtures. The presence of a direct connection between the CFM and the CNT-buckypapers is found to significantly enhance the magnetization properties revealing room temperature saturation magnetizations as high as 73 emu g⁻¹. The magnetic properties of these films are compared to those typical of cm-scale horizontally aligned and randomly oriented Fe₃C-filled CNTs buckypapers and to those observed for Fe-filled and Ni-filled CFMs. This finding has a great significance in the field of ferromagnetically filled CNTs, since it implies that the properties of α-Fe-filled CFM can be combined with those of ferromagnetically filled CNTs in a single buckypaper-structure for possible future application as a microwave absorber. The properties of the obtained films are characterized in detail with scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and vibrating sample magnetometry.