Graphene oxide: structure and temperature dependent magnetic characterization

In this report, the temperature dependent magnetic properties of graphene oxide (GO) have been studied. The graphene oxide is prepared by modified Hummer's method. The formation and structural analysis are carried out using XRD and Raman spectroscopy. Fourier transform infrared spectroscopy (FT-IR) is used to detect the presence of various functional groups. The magnetization curves as a function of the applied magnetic field at temperatures 10, 50, 150, 250 and 350 K has been accomplished. We have observed that ferrimagnetism, paramagnetism in lower temperatures along with ferromagnetism and diamagnetism in higher temperatures exist in the multilayer graphene oxide. The transition of magnetic states of GO with changing temperature is discussed based on average anisotropy energy and coupling interactions. The wrinkled structure and the defects due to the surface functional groups play a significant role in shaping magnetism in GO. The ZFC-FC curves are also analyzed to explore the system further.