TY - JOUR
T1 - Ferromagnetic correlation in hydrogen doped highly oriented pyrolytic graphite
AU - Gao, Shuai
AU - Dong, Jian
AU - Luo, Nan
AU - Grasso, Salvatore
AU - Guo, Jian
AU - Lei, Li
AU - Wen, Jiqiu
AU - Wang, Shanling
AU - Taallah, Ayoub
AU - He, Yi
AU - Odunmbaku, Omololu
AU - Boi, Filippo S.
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/11
Y1 - 2020/11
N2 - Observation of granular superconductivity in water doped graphite materials has motivated recent research because of the unexplored scenarios in the field of magnetism and spintronics. Diffusion of hydrogen and/or oxygen species has been reported to promote doping within graphitic grains; however, the origin and dynamics of the magnetic phenomena (i.e. superconductive ordering), which arise as a consequence of this doping-process, are still not well understood. In this work, we investigated the relationship between magnetic-ordering and hydrogen/oxygen doping in highly oriented pyrolytic graphite (HOPG). Diamagnetic lamellae exfoliated from HOPG were soaked in water and alcoholic beverages, with a variable ethanol concentration (0–60%). Superconducting quantum interference device (SQUID), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were employed for an in-depth characterization of undoped and doped lamellae. Presence of a hydrogen-induced ferromagnetic ordering in the π-electrons is demonstrated. To further enhance infiltration and achieve enhanced ferromagnetic signals, Isostatic-Pressure-Wine-Doping was employed. The application of pressure-induced disruption of the regular mosaic distribution within HOPG layers enhanced 1) the diffusion of the dopant within the layers and 2) the ferromagnetic response of the samples.
AB - Observation of granular superconductivity in water doped graphite materials has motivated recent research because of the unexplored scenarios in the field of magnetism and spintronics. Diffusion of hydrogen and/or oxygen species has been reported to promote doping within graphitic grains; however, the origin and dynamics of the magnetic phenomena (i.e. superconductive ordering), which arise as a consequence of this doping-process, are still not well understood. In this work, we investigated the relationship between magnetic-ordering and hydrogen/oxygen doping in highly oriented pyrolytic graphite (HOPG). Diamagnetic lamellae exfoliated from HOPG were soaked in water and alcoholic beverages, with a variable ethanol concentration (0–60%). Superconducting quantum interference device (SQUID), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were employed for an in-depth characterization of undoped and doped lamellae. Presence of a hydrogen-induced ferromagnetic ordering in the π-electrons is demonstrated. To further enhance infiltration and achieve enhanced ferromagnetic signals, Isostatic-Pressure-Wine-Doping was employed. The application of pressure-induced disruption of the regular mosaic distribution within HOPG layers enhanced 1) the diffusion of the dopant within the layers and 2) the ferromagnetic response of the samples.
KW - HOPG
KW - Hydrogen doping
KW - Magnetism
UR - http://www.scopus.com/inward/record.url?scp=85089501569&partnerID=8YFLogxK
U2 - 10.1016/j.diamond.2020.108030
DO - 10.1016/j.diamond.2020.108030
M3 - Article
AN - SCOPUS:85089501569
SN - 0925-9635
VL - 109
JO - Diamond and Related Materials
JF - Diamond and Related Materials
M1 - 108030
ER -