Records |
Author |
Wang, H.S.; Chen, L.; Elibol, K.; He, L.; Wang, H.; Chen, C.; Jiang, C.; Li, C.; Wu, T.; Cong, C.X.; Pennycook, T.J.; Argentero, G.; Zhang, D.; Watanabe, K.; Taniguchi, T.; Wei, W.; Yuan, Q.; Meyer, J.C.; Xie, X. |
Title |
Towards chirality control of graphene nanoribbons embedded in hexagonal boron nitride |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Nature Materials |
Abbreviated Journal |
Nat Mater |
Volume |
|
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
|
Pages |
1-10 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Oriented trenches are created in h-BN using different catalysts, and used as templates to grow seamlessly integrated armchair and zigzag graphene nanoribbons with chirality-dependent electrical and magnetic conductance properties. The integrated in-plane growth of graphene nanoribbons (GNRs) and hexagonal boron nitride (h-BN) could provide a promising route to achieve integrated circuitry of atomic thickness. However, fabrication of edge-specific GNRs in the lattice of h-BN still remains a significant challenge. Here we developed a two-step growth method and successfully achieved sub-5-nm-wide zigzag and armchair GNRs embedded in h-BN. Further transport measurements reveal that the sub-7-nm-wide zigzag GNRs exhibit openings of the bandgap inversely proportional to their width, while narrow armchair GNRs exhibit some fluctuation in the bandgap-width relationship. An obvious conductance peak is observed in the transfer curves of 8- to 10-nm-wide zigzag GNRs, while it is absent in most armchair GNRs. Zigzag GNRs exhibit a small magnetic conductance, while armchair GNRs have much higher magnetic conductance values. This integrated lateral growth of edge-specific GNRs in h-BN provides a promising route to achieve intricate nanoscale circuits. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000571692500001 |
Publication Date |
2020-09-21 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1476-1122; 1476-4660 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
41.2 |
Times cited |
3 |
Open Access |
Not_Open_Access |
Notes |
; H.W. and X.X. thank J.H. Edgar (Kansas State University, USA) for supplying the partial h-BN crystals. H. S. Wang, L. Chen and H. Wang thank M. Liu, X. Qiu and J. Pan from NCNT of China, F. Liou, H. Tsai, M. Crommie from UCB, USA, J. Xue and P. Yu from ShanghaiTech University and S. Wang from SJTU for nc-AFM measurement. H. S. Wang, L. Chen and H. Wang thank B. Sun and S. Li from Hunan University for the fusion of the STEM image and the electron energy loss spectroscopy mapping images. Funding: The work was partially supported by the National Key R&D program (Grant No. 2017YFF0206106), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB30000000), the National Science Foundation of China (Grant No. 51772317, 51302096, 61774040, 91964102), the Science and Technology Commission of Shanghai Municipality (Grant No. 16ZR1442700, 16ZR1402500 18511110700), Shanghai Rising-Star Program (A type) (Grant No.18QA1404800), the Hubei Provincial Natural Science Foundation of China (Grant No. ZRMS2017000370), China Postdoctoral Science Foundation (Grant No. 2017M621563, 2018T110415), and the Fundamental Research Funds of Wuhan City (No. 2016060101010075). C.L. acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grants No. 656378 – Interfacial Reactions. T.J.P. acknowledges funding from European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement no. 655760-DIGIPHASE. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan and the CREST (JPMJCR15F3), JST. C.X.C. acknowledges financial support from the National Young 1000 Talent Plan of China and the National Key R&D Program of China (No. 2018YFA0703700). L.H. acknowledges financial support from the programme of China Scholarships Council (No. 201706160037). ; |
Approved |
Most recent IF: 41.2; 2020 IF: 39.737 |
Call Number |
UA @ admin @ c:irua:171944 |
Serial |
6633 |
Permanent link to this record |
|
|
|
Author |
Mustonen, K.; Hofer, C.; Kotrusz, P.; Markevich, A.; Hulman, M.; Mangler, C.; Susi, T.; Pennycook, T.J.; Hricovini, K.; Richter, C.M.; Meyer, J.C.; Kotakoski, J.; Skákalová, V. |
Title |
Towards Exotic Layered Materials: 2D Cuprous Iodide |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Advanced materials |
Abbreviated Journal |
Adv Mater |
Volume |
|
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
|
Pages |
2106922 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Heterostructures composed of two-dimensional (2D) materials are already opening many new possibilities in such fields of technology as electronics and magnonics, but far more could be achieved if the number and diversity of 2D materials is increased. So far, only a few dozen 2D crystals have been extracted from materials that exhibit a layered phase in ambient conditions, omitting entirely the large number of layered materials that may exist in other temperatures and pressures. Here, we demonstrate how these structures can be stabilized in 2D van der Waals stacks under room temperature via growing them directly in graphene encapsulation by using graphene oxide as the template material. Specifically, we produce an ambient stable 2D structure of copper and iodine, a material that normally only occurs in layered form at elevated temperatures between 645 and 675 K. Our results establish a simple route to the production of more exotic phases of materials that would otherwise be difficult or impossible to stabilize for experiments in ambient. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000744012500001 |
Publication Date |
2021-12-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0935-9648 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
19.791 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
We acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme Grant agreements No.~756277-ATMEN (A.M. and T.S.) and No.802123-HDEM (C.H. and T.J.P.). Computational resources from the Vienna Scientific Cluster (VSC) are gratefully acknowledged. V.S. was supported by the Austrian Science Fund (FWF) (project no. I2344-N36), the Slovak Research and Development Agency (APVV-16-0319), the project CEMEA of the Slovak Academy of Sciences, ITMS project code 313021T081 of the Research & Innovation Operational Programme and from the V4-Japan Joint Research Program (BGapEng). J.K. acknowledges the FWF funding within project P31605-N36 and M.H. the funding from Slovak Research and Development Agency via the APVV-15-0693 and APVV-19-0365 project grants. Danubia NanoTech s.r.o. has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101008099 (CompSafeNano project) and also thanks Mr. Kamil Bernath for his support. |
Approved |
Most recent IF: 19.791 |
Call Number |
EMAT @ emat @c:irua:183956 |
Serial |
6834 |
Permanent link to this record |
|
|
|
Author |
Pennycook, T.J.; Martinez, G.T.; Nellist, P.D.; Meyer, J.C. |
Title |
High dose efficiency atomic resolution imaging via electron ptychography |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
196 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
196 |
Pages |
131-135 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Radiation damage places a fundamental limitation on the ability of microscopy to resolve many types of materials at high resolution. Here we evaluate the dose efficiency of phase contrast imaging with electron ptychography. The method is found to be far more resilient to temporal incoherence than conventional and spherical aberration optimized phase contrast imaging, resulting in significantly greater clarity at a given dose. This robustness is explained by the presence of achromatic lines in the four dimensional ptychographic dataset. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000451180800018 |
Publication Date |
2018-10-18 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
1 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ admin @ c:irua:165939 |
Serial |
6301 |
Permanent link to this record |
|
|
|
Author |
Susi, T.; Madsen, J.; Ludacka, U.; Mortensen, J.J.; Pennycook, T.J.; Lee, Z.; Kotakoski, J.; Kaiser, U.; Meyer, J.C. |
Title |
Efficient first principles simulation of electron scattering factors for transmission electron microscopy |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
197 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
197 |
Pages |
16-22 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Electron microscopy is a powerful tool for studying the properties of materials down to their atomic structure. In many cases, the quantitative interpretation of images requires simulations based on atomistic structure models. These typically use the independent atom approximation that neglects bonding effects, which may, however, be measurable and of physical interest. Since all electrons and the nuclear cores contribute to the scattering potential, simulations that go beyond this approximation have relied on computationally highly demanding all-electron calculations. Here, we describe a new method to generate ab initio electrostatic potentials when describing the core electrons by projector functions. Combined with an interface to quantitative image simulations, this implementation enables an easy and fast means to model electron scattering. We compare simulated transmission electron microscopy images and diffraction patterns to experimental data, showing an accuracy equivalent to earlier all-electron calculations at a much lower computational cost. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000456311700003 |
Publication Date |
2018-11-12 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
3 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ admin @ c:irua:165938 |
Serial |
6296 |
Permanent link to this record |
|
|
|
Author |
Chen, L.; Elibol, K.; Cai, H.; Jiang, C.; Shi, W.; Chen, C.; Wang, H.S.; Wang, X.; Mu, X.; Li, C.; Watanabe, K.; Taniguchi, T.; Guo, Y.; Meyer, J.C.; Wang, H. |
Title |
Direct observation of layer-stacking and oriented wrinkles in multilayer hexagonal boron nitride |
Type |
A1 Journal article |
Year |
2021 |
Publication |
2d Materials |
Abbreviated Journal |
2D Mater |
Volume |
8 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
2 |
Pages |
024001 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Hexagonal boron nitride (h-BN) has long been recognized as an ideal substrate for electronic devices due to its dangling-bond-free surface, insulating nature and thermal/chemical stability. These properties of the h-BN multilayer are mainly determined by its lattice structure. Therefore, to analyse the lattice structure and orientation of h-BN crystals becomes important. Here, the stacking order and wrinkles of h-BN are investigated by transmission electron microscopy. It is experimentally confirmed that the layers in the h-BN flakes are arranged in the AA ' stacking. The wrinkles in a form of threefold network throughout the h-BN crystal are oriented along the armchair direction, and their formation mechanism was further explored by molecular dynamics simulations. Our findings provide a deep insight about the microstructure of h-BN and shed light on the structural design/electronic modulations of two-dimensional crystals. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000605937500001 |
Publication Date |
2020-12-16 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2053-1583 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.937 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 6.937 |
Call Number |
UA @ admin @ c:irua:174950 |
Serial |
6723 |
Permanent link to this record |
|
|
|
Author |
Leuthner, G.T.; Hummel, S.; Mangler, C.; Pennycook, T.J.; Susi, T.; Meyer, J.C.; Kotakoski, J. |
Title |
Scanning transmission electron microscopy under controlled low-pressure atmospheres |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Ultramicroscopy |
Abbreviated Journal |
Ultramicroscopy |
Volume |
203 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
203 |
Pages |
76-81 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Transmission electron microscopy (TEM) is carried out in vacuum to minimize the interaction of the imaging electrons with gas molecules while passing through the microscope column. Nevertheless, in typical devices, the pressure remains at 10(-7) mbar or above, providing a large number of gas molecules for the electron beam to crack, which can lead to structural changes in the sample. Here, we describe experiments carried out in a modified scanning TEM (STEM) instrument, based on the Nion UltraSTEM 100. In this instrument, the base pressure at the sample is around 2 x 10(-10 )mbar, and can be varied up to 10(-6) mbar through introduction of gases directly into the objective area while maintaining atomic resolution imaging conditions. We show that air leaked into the microscope column during the experiment is efficient in cleaning graphene samples from contamination, but ineffective in damaging the pristine lattice. Our experiments also show that exposure to O(2 )and H2O lead to a similar result, oxygen providing an etching effect nearly twice as efficient as water, presumably due to the two 0 atoms per molecule. H(2 )and N-2 environments have no influence on etching. These results show that the residual gas environment in typical TEM instruments can have a large influence on the observations, and show that chemical etching of carbon-based structures can be effectively carried out with oxygen. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000465021000010 |
Publication Date |
2019-02-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0304-3991 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
2.843 |
Times cited |
4 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 2.843 |
Call Number |
UA @ admin @ c:irua:165937 |
Serial |
6321 |
Permanent link to this record |