Ray Sekhar Chandra, Mishra Dilip Kumar, Pong W F
Department of Physics, Faculty of Engineering and Technology (ITER), Siksha 'O' Anusandhan Deemed to be University Bhubaneswar 751 030 Odisha India
Department of Physics, CSET, University of South Africa Florida Science Campus, Private Bag X6, Florida, 1710, Christiaan de Wet and Pioneer Avenue, Florida Park Johannesburg South Africa.
RSC Adv. 2024 Aug 20;14(36):26302-26307. doi: 10.1039/d4ra04420g. eCollection 2024 Aug 16.
This study investigated the electric polarization and magnetic behaviours of various graphene-based materials, including hydrogenated graphene (H-graphene), multi-wall carbon nanotubes (MWCNTs), and reduced graphene oxide (r-GO). Results showed that MWCNTs exhibit higher magnetization, with a magnetic squareness ( / ) of approximately ≈0.5, compared to H-graphene (≈0.25). H-graphene exhibits the highest electric polarization compared to MWCNTs/r-GO, whereas r-GO demonstrates the lowest levels of polarization and magnetization compared to H-graphene/MWCNTs. The valence band maximum (4.08 eV for MWCNTs, 4.26 eV for H-graphene, and 4.78 eV for r-GO) in quasi-localized states at the Fermi level results in defects in the graphene-based lattice, which are associated with dipole moment and lead to alterations in magnetic behaviours. Different density of states (DOS) is attributed from the ultra-violet photoelectron spectra and the small variations in the Fermi edge is observed in H-graphene, MWCNTs, and r-GO are responsible for the observed magnetisation and polarizations. The unique polarization/magnetization behaviours present an opportunity for potential exploitation in storage and information processing technologies in the science and engineering community.
本研究调查了包括氢化石墨烯（H-石墨烯）、多壁碳纳米管（MWCNT）和还原氧化石墨烯（r-GO）在内的各种石墨烯基材料的电极化和磁行为。结果表明，与H-石墨烯（≈0.25）相比，MWCNT表现出更高的磁化强度，磁矩形比（/）约为≈0.5。与MWCNT/r-GO相比，H-石墨烯表现出最高的电极化，而与H-石墨烯/MWCNT相比，r-GO表现出最低水平的极化和磁化。费米能级准局域态中的价带最大值（MWCNT为4.08 eV，H-石墨烯为4.26 eV，r-GO为4.78 eV）导致石墨烯基晶格中的缺陷，这些缺陷与偶极矩相关并导致磁行为的改变。紫外光电子能谱归因于不同的态密度（DOS），并且在H-石墨烯、MWCNT和r-GO中观察到费米边缘的微小变化，这是观察到的磁化和极化的原因。独特的极化/磁化行为为科学和工程领域的存储和信息处理技术的潜在开发提供了机会。
