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Achieving ferromagnetic ordering in two-dimensional carbon semiconductors like graphdiyne remains a challenge in spintronics. We synthesized Ni-doped graphdiyne (Ni-GDY) using an electrochemical method and found that adjusting the Ni atom concentration allows for a transition from paramagnetism to ferromagnetism, with a high Curie temperature of 175 K. Our density functional theory calculations revealed that the magnetic moment in Ni-GDY arises from Ni quantum dots. At low concentrations, the distant quantum dots result in paramagnetism, while at high concentrations, the formation of bound polarons and long-range exchange coupling through carbon p orbitals leads to ferromagnetism. This study clarifies the contradiction in magnetism observed in various transition metal-doped graphdiyne materials and highlights the potential applications of Ni-doped graphdiyne in electronic devices. [ABSTRACT FROM AUTHOR]

To synthesize nonmetallic magnets containing exclusively s -p orbitals with high magnetic moments and magnetic ordering is a great challenge in physics and material science. In this study, we report increased localized spin magnetic moments and observation of ferromagnetic ordering by annealing of fluorographene. It is found that the magnetic properties is sensitive to fluorine (F) distribution. The samples annealed at ca. 400–450 °C exhibits an interesting ferromagnetic state, attributing to the fragmentizing of big F clusters into many small F domains after thermo defluorination. There are high-intensity magnetic moments in the annealed samples because of the enhanced edge effect of small F clusters, which contribute to the magnetic ordering in fluorographene for a shrunken average spacing between localized moments. The increasing structure defects after annealing can be as new centers of small F domains, and greatly stabilize magnetically ordered state. [ABSTRACT FROM AUTHOR]

Density functional theory calculations were used to study the structural, electronic, and magnetic properties of double-side partially fluorinated graphene. Both even and uneven fluorinated structures examined. It is found that midgap states and magnetic moments only appear in the uneven double-side fluorinated graphene. The magnetic moments mainly come from the carbon atoms at the edge of the fluorinated region in unevenly double-side fluorinated graphene. The dependence of magnetic moments on external tensile strain was also examined, which shows that the induced magnetic moments can be significantly increased by increasing the tensile strain. [ABSTRACT FROM AUTHOR]

To identify the effects of phosphorus on the magnetism of WS 2 , the magnetic properties of phosphatized WS 2 (P-WS 2) nanosheets with varying phosphorus concentrations are studied by experimental research and first-principle calculations. Our experimental findings demonstrate that all P-WS 2 samples exhibit distinct ordered-magnetic signatures (ferromagnetic and antiferromagnetic), and the saturation magnetization varies with the phosphorus concentration. First-principle calculations reveal that phosphorus atoms preferentially occupy sulfur vacancies, inducing magnetic moments in WS 2 nanosheets. Phosphorus atoms occupying sulfur vacancies in the same sulfur atom layer exhibit ferromagnetic coupling, while those in two sulfur atom layers of a monolayer exhibit antiferromagnetic coupling. The magnetic properties of P-WS 2 can be tuned by controlling the position and concentration of phosphorus atoms. Increasing the concentration of phosphorus atoms occupying sulfur vacancies in the same sulfur atom layer is a viable approach to enhance the magnetism of P-WS 2. This study clarifies the effects of phosphorus on the magnetism of WS 2 nanosheets and will promote its application in spintronics. • The effects of phosphorus on the magnetic properties of WS 2 was clarified. • P-WS 2 exhibits ordered magnetic signatures, and its saturation magnetization varies with the concentration of phosphorus. • P in S vacancies induce magnetic moments in WS 2 , and the magnetic coupling effects can be tuned by controlling P position. • Increasing the concentration of P in S vacancies of the same S atom layer would effectively enhance the magnetism of WS 2. [ABSTRACT FROM AUTHOR]

Inducing robust magnetic moments on the basal plane of the graphene sheet is very difficult, and is one of the greatest challenges in the study of physical chemistry of graphene materials. Theoretical studies predicted that introduction of a kind of sp3-type defects formed by OH groups is an effective pathway to achieve this goal [Boukhvalov, D. W. &Katsnelson, M. I. ACS Nano 5, 2440-2446 (2011)]. Here we demonstrate that OH groups can efficiently induce robust magnetic moments on the basal plane of the graphene sheet. We show that the inducing efficiency can reach as high as 217 μB per 1000 OH groups. More interestingly, the magnetic moments are robust and can survive even at 900°C. Our findings highlight the importance of OH group as an effective sp3-type candidate for inducing robust magnetic moments on the basal plane of the graphene sheet. [ABSTRACT FROM AUTHOR]

• The effect of thermal annealing on the magnetic properties of GOQDs was clarified. • All the annealed GOQDs samples show paramagnetism. • The magnetic moment and the magnetic density vary with the annealing temperature. • The main magnetic source of the annealed GOQDs change with the annealing temperature. The magnetism of graphene oxide quantum dots (GOQDs) has attracted much attention for the prospective applications in spintronics, which is relevant to the oxidation degree. Although the oxidation degree of GOQDs can be tuned by altering the annealing temperature, the specific effect of thermal annealing on the magnetic properties of GOQDs have not been identified. In this study, we report the effect of thermal annealing on the magnetic properties of GOQDs. All the annealed GOQDs samples show paramagnetism. Hydroxyl groups and vacancies on the basal-plane, and the phenolic hydroxyl passivated zigzag edges give various contribution to the magnetism determined by the annealing temperature. Our studies clarified the effect of thermal annealing on the magnetic properties of GOQDs, that would give benefits to their prospective applications in spintronics. [ABSTRACT FROM AUTHOR]