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Michal L, Roy R, Holec D, Gómez IJ, Pizúrová N, Nečas D, Dolečková A, Medalová J, Lepcio P, Zajíčková L. Long-Range Magnetic Order in Nickel Hydroxide-Functionalized Graphene Quantum Dots. J Phys Chem Lett 2022; 13:11536-11542. [PMID: 36475701 DOI: 10.1021/acs.jpclett.2c02964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In this work, we demonstrate the prospect of chemically synthesizing transition metal (Ni) doped magnetic graphene quantum dots (GQDs) with the sole aim of shedding light on their magnetic properties. Our results show that adsorption of nickel hydroxide on predominantly paramagnetic GQDs reveals antiferromagnetic ordering in the M-T profile around 10 K with change of the spin exchange coupling deviating from J = 1/2 to J = 1, mainly arising from the d-p mixing hybridization between the p orbital of carbon from the GQD and the d orbital of Ni. Furthermore, our results are well complemented by ab initio simulations showing asymmetry of the up and down spins around the Fermi level for nickel hydroxide-doped GQDs with long-range spin polarization. Furthermore, the magnitude of the net magnetic moment generated for doped GQDs on the carbon atoms is found to be site-dependent (surface or edge).
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Affiliation(s)
- Lukáš Michal
- CEITEC, Masaryk University, Kamenice 5, 62500Brno, Czech Republic
| | - Rajarshi Roy
- CEITEC, Masaryk University, Kamenice 5, 62500Brno, Czech Republic
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700Leoben, Austria
| | - I Jénnifer Gómez
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137Brno, Czech Republic
| | - Naděžda Pizúrová
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 61662Brno, Czech Republic
| | - David Nečas
- Central European Institute of Technology - CEITEC, Brno University of Technology, Purkyňova 123, 61200Brno, Czech Republic
| | - Anna Dolečková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500Brno, Czech Republic
| | - Jiřina Medalová
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500Brno, Czech Republic
| | - Petr Lepcio
- Central European Institute of Technology - CEITEC, Brno University of Technology, Purkyňova 123, 61200Brno, Czech Republic
| | - Lenka Zajíčková
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137Brno, Czech Republic
- Central European Institute of Technology - CEITEC, Brno University of Technology, Purkyňova 123, 61200Brno, Czech Republic
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Fan M, Wu J, Yuan J, Deng L, Zhong N, He L, Cui J, Wang Z, Behera SK, Zhang C, Lai J, Jawdat BI, Vajtai R, Deb P, Huang Y, Qian J, Yang J, Tour JM, Lou J, Chu CW, Sun D, Ajayan PM. Doping Nanoscale Graphene Domains Improves Magnetism in Hexagonal Boron Nitride. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805778. [PMID: 30687974 DOI: 10.1002/adma.201805778] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/12/2018] [Indexed: 05/12/2023]
Abstract
Carbon doping can induce unique and interesting physical properties in hexagonal boron nitride (h-BN). Typically, isolated carbon atoms are doped into h-BN. Herein, however, the insertion of nanometer-scale graphene quantum dots (GQDs) is demonstrated as whole units into h-BN sheets to form h-CBN. The h-CBN is prepared by using GQDs as seed nucleations for the epitaxial growth of h-BN along the edges of GQDs without the assistance of metal catalysts. The resulting h-CBN sheets possess a uniform distrubution of GQDs in plane and a high porosity macroscopically. The h-CBN tends to form in small triangular sheets which suggests an enhanced crystallinity compared to the h-BN synthesized under the same conditions without GQDs. An enhanced ferromagnetism in the h-CBN emerges due to the spin polarization and charge asymmetry resulting from the high density of CN and CB bonds at the boundary between the GQDs and the h-BN domains. The saturation magnetic moment of h-CBN reaches 0.033 emu g-1 at 300 K, which is three times that of as-prepared single carbon-doped h-BN.
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Affiliation(s)
- Mengmeng Fan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
- Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jingjie Wu
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Jiangtan Yuan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Liangzi Deng
- Texas Center for Superconductivity, University of Houston, Houston, TX, 77004, USA
| | - Ning Zhong
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Liang He
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, China
| | - Jiewu Cui
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Zixing Wang
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Sushant Kumar Behera
- Advanced Functional Material Laboratory, Department of Physics, Tezpur University (Central University), Tezpur, 784028, India
| | - Chenhao Zhang
- Department of Chemistry, Rice University, Houston, TX, 77005, USA
| | - Jiawei Lai
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - BenMaan I Jawdat
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Robert Vajtai
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Pritam Deb
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
- Advanced Functional Material Laboratory, Department of Physics, Tezpur University (Central University), Tezpur, 784028, India
| | - Yang Huang
- Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jieshu Qian
- Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Jiazhi Yang
- Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - James M Tour
- Department of Chemistry, Rice University, Houston, TX, 77005, USA
| | - Jun Lou
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
| | - Ching-Wu Chu
- Texas Center for Superconductivity, University of Houston, Houston, TX, 77004, USA
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Dongping Sun
- Chemicobiology and Functional Materials Institute, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Pulickel M Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, 77005, USA
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