“…The peaks corresponding to the carbon nanotubes ( Figure 1a) appear at 26.10° and 44.70°, and correspond to the diffraction planes (002) and (100). 28,29 Regarding the diffractogram of iron oxide (Figure 1b), characteristic peaks of magnetite and maghemite are observed, being indistinguishable by XRD. 30 The main peaks of magnetite-maghemite were observed at 30.10°, 35.50°, 43.10°, 53.40°, 57.04° and 62.88°, representing the diffraction planes (220), (311), (400), (422), (511) and (440), respectively.…”