Ziying Wang
Position: Grad Students
Affiliation: NUS Centre for Advanced 2D Materials
Research Type: Experiment
Office: MD1
Email: a0112448@u.nus.edu
CA2DM Publications:
2024 |
Lyu, Pin; Wang, Ziying; Guo, Na; Su, Jie; Li, Jing; Qi, Dongchen; Xi, Shibo; Lin, Huihui; Zhang, Qihan; Pennycook, Stephen J; Chen, Jingsheng; Zhao, Xiaoxu; Zhang, Chun; Loh, Kian Ping; Lu, Jiong Air-Stable Wafer-Scale Ferromagnetic Metallo-Carbon Nitride Monolayer Journal Article JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 146 (30), pp. 20604-20614, 2024, ISSN: 0002-7863. @article{ISI:001272808300001, title = {Air-Stable Wafer-Scale Ferromagnetic Metallo-Carbon Nitride Monolayer}, author = {Pin Lyu and Ziying Wang and Na Guo and Jie Su and Jing Li and Dongchen Qi and Shibo Xi and Huihui Lin and Qihan Zhang and Stephen J Pennycook and Jingsheng Chen and Xiaoxu Zhao and Chun Zhang and Kian Ping Loh and Jiong Lu}, doi = {10.1021/jacs.4c02160}, times_cited = {2}, issn = {0002-7863}, year = {2024}, date = {2024-07-18}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {146}, number = {30}, pages = {20604-20614}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {The pursuit of robust, long-range magnetic ordering in two-dimensional (2D) materials holds immense promise for driving technological advances. However, achieving this goal remains a grand challenge due to enhanced quantum and thermal fluctuations as well as chemical instability in the 2D limit. While magnetic ordering has been realized in atomically thin flakes of transition metal chalcogenides and metal halides, these materials often suffer from air instability. In contrast, 2D carbon-based materials are stable enough, yet the challenge lies in creating a high density of local magnetic moments and controlling their long-range magnetic ordering. Here, we report a novel wafer-scale synthesis of an air-stable metallo-carbon nitride monolayer (MCN, denoted as MN4/CNx), featuring ultradense single magnetic atoms and exhibiting robust room-temperature ferromagnetism. Under low-pressure chemical vapor deposition conditions, thermal dehydrogenation and polymerization of metal phthalocyanine (MPc) on copper foil at elevated temperature generate a substantial number of nitrogen coordination sites for anchoring magnetic single atoms in monolayer MN4/CNx (where M = Fe, Co, and Ni). The incorporation of densely populating MN4 sites into monolayer MCN networks leads to robust ferromagnetism up to room temperature, enabling the observation of anomalous Hall effects with excellent chemical stability. Detailed electronic structure calculations indicate that the presence of high-density metal sites results in the emergence of spin-split d-bands near the Fermi level, causing a favorable long-range ferromagnetic exchange coupling through direct exchange interactions. Our work demonstrates a novel synthesis approach for wafer-scale MCN monolayers with robust room-temperature ferromagnetism and may shed light on practical electronic and spintronic applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The pursuit of robust, long-range magnetic ordering in two-dimensional (2D) materials holds immense promise for driving technological advances. However, achieving this goal remains a grand challenge due to enhanced quantum and thermal fluctuations as well as chemical instability in the 2D limit. While magnetic ordering has been realized in atomically thin flakes of transition metal chalcogenides and metal halides, these materials often suffer from air instability. In contrast, 2D carbon-based materials are stable enough, yet the challenge lies in creating a high density of local magnetic moments and controlling their long-range magnetic ordering. Here, we report a novel wafer-scale synthesis of an air-stable metallo-carbon nitride monolayer (MCN, denoted as MN4/CNx), featuring ultradense single magnetic atoms and exhibiting robust room-temperature ferromagnetism. Under low-pressure chemical vapor deposition conditions, thermal dehydrogenation and polymerization of metal phthalocyanine (MPc) on copper foil at elevated temperature generate a substantial number of nitrogen coordination sites for anchoring magnetic single atoms in monolayer MN4/CNx (where M = Fe, Co, and Ni). The incorporation of densely populating MN4 sites into monolayer MCN networks leads to robust ferromagnetism up to room temperature, enabling the observation of anomalous Hall effects with excellent chemical stability. Detailed electronic structure calculations indicate that the presence of high-density metal sites results in the emergence of spin-split d-bands near the Fermi level, causing a favorable long-range ferromagnetic exchange coupling through direct exchange interactions. Our work demonstrates a novel synthesis approach for wafer-scale MCN monolayers with robust room-temperature ferromagnetism and may shed light on practical electronic and spintronic applications. |