npj 2D Materials and Applications最新文献_第10页

Magnetic properties of intercalated quasi-2D Fe3-xGeTe2 van der Waals magnet 插层准二维 Fe3-xGeTe2 范德华磁体的磁特性

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-08-21 DOI: 10.1038/s41699-023-00417-w

Hector Iturriaga, Luis M. Martinez, Thuc T. Mai, Adam J. Biacchi, Mathias Augustin, Angela R. Hight Walker, Mohamed Fathi Sanad, Sreeprasad T. Sreenivasan, Yu Liu, Elton J. G. Santos, Cedomir Petrovic, Srinivasa R. Singamaneni

{"title":"Magnetic properties of intercalated quasi-2D Fe3-xGeTe2 van der Waals magnet","authors":"Hector Iturriaga, Luis M. Martinez, Thuc T. Mai, Adam J. Biacchi, Mathias Augustin, Angela R. Hight Walker, Mohamed Fathi Sanad, Sreeprasad T. Sreenivasan, Yu Liu, Elton J. G. Santos, Cedomir Petrovic, Srinivasa R. Singamaneni","doi":"10.1038/s41699-023-00417-w","DOIUrl":"10.1038/s41699-023-00417-w","url":null,"abstract":"Among several well-known transition metal-based compounds, cleavable van der Waals (vdW) Fe3-xGeTe2 (FGT) magnet is a strong candidate for use in two-dimensional (2D) magnetic devices due to its strong perpendicular magnetic anisotropy, sizeable Curie temperature (TC ~154 K), and versatile magnetic character that is retained in the low-dimensional limit. While the TC remains far too low for practical applications, there has been a successful push toward improving it via external driving forces such as pressure, irradiation, and doping. Here we present experimental evidence of a room temperature (RT) ferromagnetic phase induced by the electrochemical intercalation of common tetrabutylammonium cations (TBA+) into quasi-2D FGT. We obtained Curie temperatures as high as 350 K with chemical and physical stability of the intercalated compound. The temperature-dependent Raman measurements, in combination with vdW-corrected ab initio calculations, suggest that charge transfer (electron doping) upon intercalation could lead to the observation of RT ferromagnetism. This work demonstrates that molecular intercalation is a viable route in realizing high-temperature vdW magnets in an inexpensive and reliable manner, and has the potential to be extended to bilayer and few-layer vdW magnets.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00417-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57548917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beryllene, the lightest Xene Beryllene，最轻的Xene

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-08-18 DOI: 10.1038/s41699-023-00415-y

Sumit Chahal, Arkamita Bandyopadhyay, Chan-Shan Yang, Prashant Kumar

{"title":"Beryllene, the lightest Xene","authors":"Sumit Chahal, Arkamita Bandyopadhyay, Chan-Shan Yang, Prashant Kumar","doi":"10.1038/s41699-023-00415-y","DOIUrl":"10.1038/s41699-023-00415-y","url":null,"abstract":"After the discovery of sp2-hybridized graphene and even lighter borophene, the scientific quest for the thinnest metallic sheets prompts the discovery of beryllene. As beryllium lacks p-electrons, the hybridization and structural evolution of beryllene in determining electronic/excitonic behaviors are scientifically interesting. Herein, we report the experimental realization of freestanding flat beryllene sheets with a lateral dimension of ~0.2–4 μm via sonochemical exfoliation. High-resolution transmission electron microscopy establishes the existence of hexagonal, square and stripe crystallographic phases. While characteristic Raman fingerprints ~451 and ~614 cm−1, and experimentally observed electrically metallic nature of beryllene (vindicated by density-functional-theory band structure calculations) establish beryllene synthesis. Room temperature magnetism in Be-G and Be-CNT hybrids (established by Raman mapping and magnetic force microscopic imaging) is an interesting finding. Beryllene was explored as a surface-enhanced Raman spectroscopy (SERS) anchor in molecular sensing, oxidation-resistant, and fire-resistant laminates. It is believed that the discovery of beryllene will lead to novel functionalities and emerging applications.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00415-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45800774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Room temperature multiferroicity in a transition metal dichalcogenide 过渡金属二硫化物的室温多铁性

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-08-17 DOI: 10.1038/s41699-023-00416-x

G. Cardenas-Chirivi, K. Vega-Bustos, H. Rojas-Páez, D. Silvera-Vega, J. Pazos, O. Herrera, M. A. Macías, C. Espejo, W. López-Pérez, J. A. Galvis, P. Giraldo-Gallo

引用次数: 0

Layer control of Sr1.8Bi0.2Nan-3NbnO3n+1 (n = 3–5) perovskite nanosheets: dielectric to ferroelectric transition of film deposited by Langmuir Blodgett method Sr1.8Bi0.2Nan-3NbnO3n+1 (n = 3-5)钙钛矿纳米片的层控制:Langmuir Blodgett法沉积薄膜的介电到铁电转变

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-08-11 DOI: 10.1038/s41699-023-00418-9

So-Yeon Yoo, Haena Yim, Ahrom Ryu, Chansoo Yoon, Bae Ho Park, Sahn Nahm, Ji-Won Choi

{"title":"Layer control of Sr1.8Bi0.2Nan-3NbnO3n+1 (n = 3–5) perovskite nanosheets: dielectric to ferroelectric transition of film deposited by Langmuir Blodgett method","authors":"So-Yeon Yoo, Haena Yim, Ahrom Ryu, Chansoo Yoon, Bae Ho Park, Sahn Nahm, Ji-Won Choi","doi":"10.1038/s41699-023-00418-9","DOIUrl":"10.1038/s41699-023-00418-9","url":null,"abstract":"Solution-based processable high-k 2-dimensional (2D) ferroelectrics have attracted significant interest for use in next-generation nanoelectronics. Although few studies on potential 2D ferroelectric nanosheets in local areas have been conducted, reports on the thin-film characteristics applicable to the device are insufficient. In this study, we successfully synthesize high-k 2D Sr1.8Bi0.2Nan-3NbnO3n+1 (octahedral units, n = 3–5) nanosheets by the engineering of the n of NbO6 octahedral layers with A-site modification, and realized ferroelectric characteristics in ultrathin films (below 10 nm). The nanosheets are synthesized by a solution-based cation exchange process and deposited using the Langmuir-Blodgett (LB) method. As increasing the NbO6 octahedral layer, the thickness of the nanosheets increased and the band gaps are tuned to 3.80 eV (n = 3), 3.76 eV (n = 4), and 3.70 eV (n = 5). In addition, the dielectric permittivity of the 5-layer stacked nanofilm increase to 26 (n = 3), 33 (n = 4), and 62 (n = 5). In particular, the increased perovskite layer exhibits large distortions due to the size mismatch of Sr/Bi/Na ions at the A-site and promotes local ferroelectric instability due to its spontaneous polarization along the c-axis caused by an odd n number. We investigate the stable ferroelectricity in Pt/ 5-layer Sr1.8Bi0.2Na2Nb5O16 / Nb:STO capacitor by polarization-electric field (P-E) hysteresis; the coercive electric field (Ec) was 338 kV cm−1 and the remnant polarization (Pr) 2.36 μC cm−2. The ferroelectric properties of ultrathin 2D materials could drive interesting innovations in next-generation electronics.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00418-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45652312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electron transport and scattering mechanisms in ferromagnetic monolayer Fe3GeTe2 铁磁单层Fe3GeTe2中的电子输运和散射机制

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-08-07 DOI: 10.1038/s41699-023-00413-0

Danis I. Badrtdinov, Georgy V. Pushkarev, Mikhail I. Katsnelson, Alexander N. Rudenko

引用次数: 1

Essential role of momentum-forbidden dark excitons in the energy transfer responses of monolayer transition-metal dichalcogenides 动量禁止暗激子在单层过渡金属二硫族化合物能量转移响应中的重要作用

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-07-25 DOI: 10.1038/s41699-023-00414-z

Jhen-Dong Lin, Ping-Yuan Lo, Guan-Hao Peng, Wei-Hua Li, Shiang-Yu Huang, Guang-Yin Chen, Shun-Jen Cheng

{"title":"Essential role of momentum-forbidden dark excitons in the energy transfer responses of monolayer transition-metal dichalcogenides","authors":"Jhen-Dong Lin, Ping-Yuan Lo, Guan-Hao Peng, Wei-Hua Li, Shiang-Yu Huang, Guang-Yin Chen, Shun-Jen Cheng","doi":"10.1038/s41699-023-00414-z","DOIUrl":"10.1038/s41699-023-00414-z","url":null,"abstract":"We present a theoretical investigation of exciton-mediated Förster resonant energy transfers (FRET’s) from photoexcited quantum dots (QD’s) to transition-metal dichalcogenide monolayers (TMD-ML’s), implemented by the quantum theory of FRET on the base of first-principles-calculated exciton fine structures. With the enhanced electron-hole Coulomb interactions, atomically thin TMD-MLs are shown to serve as an exceptional platform for FRET that are mediated purely by excitons and take full advantage of the superior excitonic properties. Remarkably, the energy-transfer responses of atomically thin TMD-ML’s are shown to be dictated by the momentum-forbidden dark excitons rather than the commonly recognized bright ones. Specifically, the longitudinal dark exciton states following the exchange-driven light-like linear band dispersion play a key role in grading up the efficiency and robustness of FRET of TMD-ML against the inhomogeneity of QD-donor ensembles. With the essential involvement of dark excitons, the FRET responses of TMD-ML’s no longer follow the distance power law as classically predicted and, notably, cannot manifest the dimensionality of the donor-acceptor system.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00414-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47548456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Anomalous conductance quantization of a one-dimensional channel in monolayer WSe2 单层WSe2中一维通道的异常电导量子化

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-07-15 DOI: 10.1038/s41699-023-00407-y

Justin Boddison-Chouinard, Alex Bogan, Pedro Barrios, Jean Lapointe, Kenji Watanabe, Takashi Taniguchi, Jarosław Pawłowski, Daniel Miravet, Maciej Bieniek, Pawel Hawrylak, Adina Luican-Mayer, Louis Gaudreau

{"title":"Anomalous conductance quantization of a one-dimensional channel in monolayer WSe2","authors":"Justin Boddison-Chouinard, Alex Bogan, Pedro Barrios, Jean Lapointe, Kenji Watanabe, Takashi Taniguchi, Jarosław Pawłowski, Daniel Miravet, Maciej Bieniek, Pawel Hawrylak, Adina Luican-Mayer, Louis Gaudreau","doi":"10.1038/s41699-023-00407-y","DOIUrl":"10.1038/s41699-023-00407-y","url":null,"abstract":"Among quantum devices based on 2D materials, gate-defined quantum confined 1D channels are much less explored, especially in the high-mobility regime where many-body interactions play an important role. We present the results of measurements and theory of conductance quantization in a gate-defined one-dimensional channel in a single layer of transition metal dichalcogenide material WSe2. In the quasi-ballistic regime of our high-mobility sample, we report conductance quantization steps in units of e2/h for a wide range of carrier concentrations. Magnetic field measurements show that as the field is raised, higher conductance plateaus move to accurate quantized values and then shift to lower conductance values while the e2/h plateau remains locked. Based on microscopic atomistic tight-binding theory, we show that in this material, valley and spin degeneracies result in 2 e2/h conductance steps for noninteracting holes, suggesting that symmetry-breaking mechanisms such as valley polarization dominate the transport properties of such quantum structures.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00407-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138506608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Coulomb impurities on the electronic structure of magic angle twisted bilayer graphene 库仑杂质对魔角扭曲双层石墨烯电子结构的影响

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-07-10 DOI: 10.1038/s41699-023-00403-2

Muhammad Sufyan Ramzan, Zachary A. H. Goodwin, Arash A. Mostofi, Agnieszka Kuc, Johannes Lischner

{"title":"Effect of Coulomb impurities on the electronic structure of magic angle twisted bilayer graphene","authors":"Muhammad Sufyan Ramzan, Zachary A. H. Goodwin, Arash A. Mostofi, Agnieszka Kuc, Johannes Lischner","doi":"10.1038/s41699-023-00403-2","DOIUrl":"10.1038/s41699-023-00403-2","url":null,"abstract":"In graphene, charged defects break the electron-hole symmetry and can even give rise to exotic collapse states when the defect charge exceeds a critical value which is proportional to the Fermi velocity. In this work, we investigate the electronic properties of twisted bilayer graphene (tBLG) with charged defects using tight-binding calculations. Like monolayer graphene, tBLG exhibits linear bands near the Fermi level but with a dramatically reduced Fermi velocity near the magic angle (approximately 1.1°). This suggests that the critical value of the defect charge in magic-angle tBLG should also be very small. We find that charged defects give rise to significant changes in the low-energy electronic structure of tBLG. Depending on the defect position in the moiré unit cell, it is possible to open a band gap or to induce an additional flattening of the low-energy valence and conduction bands. Our calculations suggest that the collapse states of the two monolayers hybridize in the twisted bilayer. However, their in-plane localization remains largely unaffected by the presence of the additional twisted layer because of the different length scales of the moiré lattice and the monolayer collapse state wavefunctions. These predictions can be tested in scanning tunneling spectroscopy experiments.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00403-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47769892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Theoretical prediction and shape-controlled synthesis of two-dimensional semiconductive Ni3TeO6 二维半导体Ni3TeO6的理论预测和形状控制合成

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-07-08 DOI: 10.1038/s41699-023-00412-1

Javier Fernández-Catalá, Andrey A. Kistanov, Yang Bai, Harishchandra Singh, Wei Cao

{"title":"Theoretical prediction and shape-controlled synthesis of two-dimensional semiconductive Ni3TeO6","authors":"Javier Fernández-Catalá, Andrey A. Kistanov, Yang Bai, Harishchandra Singh, Wei Cao","doi":"10.1038/s41699-023-00412-1","DOIUrl":"10.1038/s41699-023-00412-1","url":null,"abstract":"Current progress in two-dimensional (2D) materials explorations leads to constant specie enrichments of possible advanced materials down to two dimensions. The metal chalcogenide-based 2D materials are promising grounds where many adjacent territories are waiting to be explored. Here, a stable monolayer Ni3TeO6 (NTO) structure was computationally predicted and its stacked 2D nanosheets experimentally synthesized. Theoretical design undergoes featuring coordination of metalloid chalcogen, slicing the bulk structure, geometrical optimizations and stability study. The predicted layered NTO structure is realized in nanometer-thick nanosheets via a one-pot shape-controlled hydrothermal synthesis. Compared to the bulk, the 2D NTO own a lowered bandgap energy, more sensitive wavelength selectivity and an emerging photocatalytic hydrogen evolution ability under visible light. Beside a new 2D NTO with the optoelectrical and photocatalytic merits, its existing polar space group, structural specification, and design route are hoped to benefit 2D semiconductor innovations both in species enrichment and future applications.","PeriodicalId":19227,"journal":{"name":"npj 2D Materials and Applications","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41699-023-00412-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43852016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Coulomb engineering of two-dimensional Mott materials 二维莫特材料的库仑工程

IF 9.7 2区材料科学

npj 2D Materials and Applications Pub Date : 2023-07-06 DOI: 10.1038/s41699-023-00408-x

Erik G. C. P. van Loon, Malte Schüler, Daniel Springer, Giorgio Sangiovanni, Jan M. Tomczak, Tim O. Wehling

引用次数: 7