Room-temperature ferromagnetic organic magnets derived from fluoro-graphite via facile halide exchange |
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Authors: | Akshaya Kumar Swain Arpan Kumar Nayak Sungwook Mhin HyukSu Han |
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Affiliation: | 1. Delta Magnets Ltd., Nashik, Maharashtra, India;2. Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India;3. Department of Advanced Materials Engineering, Kyonggi University, Suwon, Republic of Korea;4. Department of Energy Engineering, Konkuk University, Seoul, Republic of Korea |
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Abstract: | Room-temperature ferromagnetic organic magnet is developed via a facile halide exchange process using fluoro-graphite (FG) as a starting material. Structural and chemical analysis reveals that heterogeneous C–F bond cleavage in the defect sites of FG is essentially related to the formation of ferromagnetic hydroxyl-graphene (HG). Pyrolysis of FG in a polar solvent with iodine ions induces a formation of metastable C–I bond and subsequent replacement of the I sites with the hydroxyl groups. Specifically, defective sites can be formed in FG due to nucleophile attack where the OH groups can be easily generated. As a result, the FG can be transformed into the HG with a network of sp2-conjugated carbon motifs in a sp3-based graphene matrix. Hence, the paramagnetic centers in the π-electron system of FG can be transformed to the long-range ordered ferromagnetic centers in the sp2-conjugated system of HG. Electron paramagnetic resonance data demonstrate the weak ferromagnetic property of HG stable at room temperature. |
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Keywords: | ferromagnetism halide exchange hydroxyl graphene organic magnet |
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