scholarly journals High-Resolution Measurement of Molecular Internal Polarization Structure by Photoinduced Force Microscopy

2021 ◽  
Vol 11 (15) ◽  
pp. 6937
Author(s):  
Hidemasa Yamane ◽  
Nobuhiko Yokoshi ◽  
Hajime Ishihara
Keyword(s):  
High Resolution ◽  
Single Molecule ◽  
Near Field ◽  
Critical Role ◽  
Single Molecules ◽  
Atomic Scale ◽  
Metallic Surface ◽  
Metallic Surfaces ◽  
Force Microscopy

Near-field interactions between metallic surfaces and single molecules play an essential role in the application of metamaterials. To reveal the near-field around a photo-irradiated single molecule on the metallic surface, high-resolution photo-assisted scanning microscopy is required. In this study, we theoretically propose photoinduced force microscopy (PiFM) measurements of single molecules at the atomic resolution. For experimental demonstration, we performed a numerical calculation of PiFM images of various transition states, including optical forbidden transitions, and interpreted them in terms of the interaction between the molecular internal polarization structures and localized plasmon. We also clarified the critical role of atomic-scale structures on the tip surface for high-resolution PiFM measurements.

scholarly journals Molecular-scale investigation of the oxidation behavior of chromia-forming alloys in high-temperature CO2

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Richard P. Oleksak ◽  
Rafik Addou ◽  
Bharat Gwalani ◽  
John P. Baltrus ◽  
Tao Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Power Systems ◽  
High Purity ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Critical Role ◽  
Atomic Scale ◽  
Atomic Diffusion ◽  
Carbon Transport

AbstractCurrent and future power systems require chromia-forming alloys compatible with high-temperature CO2. Important questions concerning the mechanisms of oxidation and carburization remain unanswered. Herein we shed light onto these processes by studying the very initial stages of oxidation of Fe22Cr and Fe22Ni22Cr model alloys. Ambient-pressure X-ray photoelectron spectroscopy enabled in situ analysis of the oxidizing surface under 1 mbar of flowing CO2 at temperatures up to 530 °C, while postexposure analyses revealed the structure and composition of the oxidized surface at the near-atomic scale. We found that gas purity played a critical role in the kinetics of the reaction, where high purity CO2 promoted the deposition of carbon and the selective oxidation of Cr. In contrast, no carbon deposition occurred in low purity CO2 and Fe oxidation ensued, thus highlighting the critical role of impurities in defining the early oxidation pathway of the alloy. The Cr-rich oxide formed on Fe22Cr in high purity CO2 was both thicker and more permeable to carbon compared to that formed on Fe22Ni22Cr, where carbon transport appeared to occur by atomic diffusion through the oxide. Alternatively, the Fe-rich oxide formed in low purity CO2 suggested carbon transport by molecular CO2.

scholarly journals All chemical YBa2Cu3O7 superconducting multilayers: Critical role of CeO2 cap layer flatness

2009 ◽  
Vol 24 (4) ◽  
pp. 1446-1455 ◽  
Author(s):  
M. Coll ◽  
J. Gàzquez ◽  
R. Huhne ◽  
B. Holzapfel ◽  
Y. Morilla ◽  
...  
Keyword(s):  
Critical Role ◽  
High Energy ◽  
Buffer Layers ◽  
Solution Deposition ◽  
Ybco Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Densities ◽  
Atomically Flat

New advances toward microstructural improvement of epitaxial CeO2 films grown by chemical solution deposition and their use as buffer layers for YBa2Cu3O7 (YBCO) films are presented. We demonstrate that the degree of epitaxy and the fraction of (001) atomically flat surface area are controlled by the incorporation of tetravalent (Zr4+) or trivalent (Gd3+) cations into the ceria lattice. The degree of epitaxy has been investigated by means of Rutherford backscattering spectroscopy-channeling and reflection high-energy electron diffraction, and a new methodology is also presented to quantify the fraction of (001) atomically flat area from atomic force microscopy images. Results are further correlated with the superconducting properties, microstructure, and texture of YBCO films grown by the trifluoroacetate route. A comparison with pulsed laser deposition and YBCO films grown on the same ceria layers is also presented. This growth procedure has allowed us to obtain all chemical multilayer films with controlled microstructure and critical current densities above 4 MA cm−2 at 77 K.

Critical role of atomic-scale defect disorders for high-performance nanostructured half-Heusler thermoelectric alloys and their thermal stability

2019 ◽  
Vol 180 ◽  
pp. 97-104 ◽  
Author(s):  
Ho Jae Lee ◽  
Kyu Hyoung Lee ◽  
Liangwei Fu ◽  
GyeongTak Han ◽  
Hyun-Sik Kim ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Critical Role ◽  
Atomic Scale

scholarly journals High-Resolution Correlative Microscopy: Bridging the Gap between Single Molecule Localization Microscopy and Atomic Force Microscopy

Nano Letters ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 4896-4904 ◽  
Author(s):  
Pascal D. Odermatt ◽  
Arun Shivanandan ◽  
Hendrik Deschout ◽  
Radek Jankele ◽  
Adrian P. Nievergelt ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
High Resolution ◽  
Single Molecule ◽  
Correlative Microscopy ◽  
Localization Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Single Molecule Localization Microscopy

scholarly journals Subwavelength Direct Laser Nanopatterning Via Microparticle Arrays for Functionalizing Metallic Surfaces

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Jean-Michel Romano ◽  
Rajib Ahmed ◽  
Antonio Garcia-Giron ◽  
Pavel Penchev ◽  
Haider Butt ◽  
...  
Keyword(s):  
Focal Length ◽  
Near Field ◽  
Cost Effective ◽  
Spot Size ◽  
Metallic Surface ◽  
Metallic Surfaces ◽  
Large Area ◽  
Transitional State ◽  
Direct Laser ◽  
Surface Patterns

Functionalized metallic nanofeatures can be selectively fabricated via ultrashort laser processing; however, the cost-effective large-area texturing, intrinsically constrained by the diffraction limit of light, remains a challenging issue. A high-intensity near-field phenomenon that takes place when irradiating microsized spheres, referred to as photonic nanojet (PN), was investigated in the transitional state between geometrical optics and dipole regime to fabricate functionalized metallic subwavelength features. Finite element simulations were performed to predict the PN focal length and beam spot size, and nanofeature formation. A systematic approach was employed to functionalize metallic surface by varying the pulse energy, focal offset, and number of pulses to fabricate controlled array of nanoholes and to study the generation of triangular and rhombic laser-induced periodic surface structures (LIPSS). Finally, large-area texturing was investigated to minimize the dry laser cleaning (DLC) effect and improve homogeneity of PN-assisted texturing. Tailored dimensions and densities of achievable surface patterns could provide hexagonal light scattering and selective optical reflectance for a specific light wavelength. Surfaces exhibited controlled wetting properties with either hydrophilicity or hydrophobicity. No correlation was found between wetting and microbacterial colonization properties of textured metallic surfaces after 4 h incubation of Escherichia coli. However, an unexpected bacterial repellency was observed.

scholarly journals Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips

2017 ◽  
Vol 8 ◽  
pp. 2389-2395 ◽  
Author(s):  
Sumit Tewari ◽  
Koen M Bastiaans ◽  
Milan P Allan ◽  
Jan M van Ruitenbeek
Keyword(s):  
Atomic Structure ◽  
Scanning Tunneling Microscope ◽  
Critical Role ◽  
Atomic Layer ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Stm Tips

Scanning tunneling microscopes (STM) are used extensively for studying and manipulating matter at the atomic scale. In spite of the critical role of the STM tip, procedures for controlling the atomic-scale shape of STM tips have not been rigorously justified. Here, we present a method for preparing tips in situ while ensuring the crystalline structure and a reproducibly prepared tip structure up to the second atomic layer. We demonstrate a controlled evolution of such tips starting from undefined tip shapes.

scholarly journals Linking morphology with activity through the lifetime of pretreated PtNi nanostructured thin film catalysts

2015 ◽  
Vol 3 (21) ◽  
pp. 11660-11667 ◽  
Author(s):  
D. A. Cullen ◽  
M. Lopez-Haro ◽  
P. Bayle-Guillemaud ◽  
L. Guetaz ◽  
M. K. Debe ◽  
...  
Keyword(s):  
Thin Film ◽  
High Resolution ◽  
Electron Tomography ◽  
Critical Role ◽  
High Resolution Imaging ◽  
Nanostructured Thin Film ◽  
Highly Active ◽  
Thin Film Catalysts ◽  
Resolution Imaging

High resolution imaging and electron tomography are used to link nanoscale morphology with electrochemical activity in highly active Pt3Ni7nanostructured thin film catalysts, revealing the critical role of catalyst conditioning.

scholarly journals Near-Field Spot for Localized Light-Excitation of a Single Fluorescent Molecule

2020 ◽  
Vol 10 (4) ◽  
pp. 364-374
Author(s):  
Muhammad Shemyal Nisar ◽  
Yujun Cui ◽  
Kaitong Dang ◽  
Liyong Jiang ◽  
Xiangwei Zhao
Keyword(s):  
Single Molecule ◽  
Degrees Of Freedom ◽  
Zero Mode ◽  
Near Field ◽  
3D Structure ◽  
Single Molecules ◽  
Evanescent Waves ◽  
Water Interface ◽  
Large Molecules ◽  
Light Excitation

Abstract Zero-mode waveguides have become important tools for the detection of single molecules. There are still, however, serious challenges because large molecules need to be packed into nano-holes. To circumvent this problem, we investigate and numerically simulate a novel planar sub-wavelength 3-dimension (3D) structure, which is named as near-field spot. It enables the detection of a single molecule in highly concentrated solutions. The near-field spot can produce evanescent waves at the dielectric/water interface, which exponentially decay as they travel away from the dielectric/water interface. These evanescent waves are keys for the detection of fluorescently tagged single molecules. A numerical simulation of the proposed device shows that the performance is comparable with a zero-mode waveguide. Additional degrees-of-freedom, however, can potentially supersede its performance.

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