Three-Dimensional Superlattice Packing of Faceted Silver Nanocrystals

1996 ◽  
Vol 457 ◽  
Author(s):  
S. A. Harfenist ◽  
Z. L. Wang ◽  
M. M. Alvarez ◽  
I. Vezmar ◽  
R. L. Whetten
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Self Assembled Monolayers ◽  
Microscopy Imaging ◽  
Fundamental Properties ◽  
Transmission Electron ◽  
Assembled Monolayers ◽  
Crystalline Films ◽  
Orientational Ordering ◽  
First Time

ABSTRACTOrientational ordering of faceted nanocrystals in nanocrystal arrays has been directly observed for the first time, by use of transmission electron microscopy imaging and diffraction to resolve the structure of thin molecular-crystalline films of silver nanocrystals passivated by alkylthiolate self-assembled monolayers. The type of ordering found is determined by the nanocrystals faceted morphology, as mediated by the interactions of surfactant groups tethered to the facets on neighboring nanocrystals. Orientational ordering is crucial for the understanding of the fundamental properties of quantum-dot arrays, as well as for their optimal utilization in optical and electronic applications.

Three-Dimensional Hexagonal Close-Packed Superlattices of Passivated Ag Nanocrystals

1997 ◽  
Vol 3 (S2) ◽  
pp. 431-432
Author(s):  
S. A. Harfenist ◽  
Z. L. Wang ◽  
R. L. Whetten ◽  
I. Vezmar ◽  
M. M. Alvarez ◽  
...  
Keyword(s):  
Carbon Film ◽  
Three Dimensional ◽  
Structure Characterization ◽  
Self Assembled Monolayers ◽  
Hexagonal Close Packed ◽  
Self Assembling ◽  
Transmission Electron ◽  
Assembled Monolayers ◽  
High Resolution Tem ◽  
Nanocrystal Superlattices

Silver nanocrystals passivated by dodecanethiol self-assembled monolayers were produced using an aerosol technique described in detail elsewhere [1]. Self-assembling passivated nanocrystal-superlattices (NCS's) involve self-organization into monolayers, thin films, and superlattices of size-selected nanoclusters encapsulated in a protective compact coating [2,3,4,5,6,7]. We report the preparation and structure characterization of three-dimensional (3-D) hexagonal close-packed Ag nanocrystal supercrystals from Ag nanocrystals of ˜4.5 nm in diameters. The crystallography of the superlattice and atomic core lattices were determined using transmission electron microscopy (TEM) and high-resolution TEM.SEM was used to image the nanocrystal superlattices formed on an amorphous carbon film of an TEM specimen grid (fig. la). The superlattice films show well shaped, sharply faceted, triangular shaped sheets. Figure lb depicts numerous Ag nanocrystal aggregates uniformly distributed over the imaging region. Inset in this figure is an enlargement of the boxed region at the edge of a supercrystal typifying the ordered nanocrystal packing.

scholarly journals In Situ Transmission Electron Microscopy Imaging of Electromigration in Platinum Nanowires

2013 ◽  
Vol 19 (S5) ◽  
pp. 43-48 ◽  
Author(s):  
Maria Rudneva ◽  
Bo Gao ◽  
Ferry Prins ◽  
Qiang Xu ◽  
Herre S.J. van der Zant ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Feedback Control ◽  
Three Dimensional ◽  
Dark Field ◽  
Control Mode ◽  
Microscopy Imaging ◽  
Platinum Nanowires ◽  
Transmission Electron

AbstractIn situ transmission electron microscopy was performed on the electromigration in platinum (Pt) nanowires (14 nm thick, 200 nm wide, and 300 nm long) with and without feedback control. Using the feedback control mode, symmetric electrodes are obtained and the gap usually forms at the center of the Pt nanowire. Without feedback control, asymmetric electrodes are formed, and the gap can occur at any position along the wire. The three-dimensional gap geometries of the electrodes in the Pt nanowire were determined using high-angle annular dark-field scanning transmission electron microscopy; the thickness of the nanowire is reduced from 14 nm to only a few atoms at the edge with a gap of about 5–10 nm.

Synthesis and characterization of 3D Cu0.45Mn0.55O2 nanoflowers with novel photoluminescence and magnetic properties

2014 ◽  
Vol 28 (09) ◽  
pp. 1450071
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-ain Javed ◽  
Quanshui Li ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Growth Method ◽  
First Time

In this paper, three-dimensional (3D) Cu 0.45 Mn 0.55 O 2 nanoflowers self-assembled by interconnecting dense stacked single-crystalline nanoplates have been prepared using the template-free hydrothermal growth method. The morphology, phase structure and composition of the as-prepared nanomaterial were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) with selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDX). FESEM and TEM analyses show that the size of 3D Cu 0.45 Mn 0.55 O 2 nanoflowers is in the range of 1–1.5 μm and the thickness of interconnected nanoplates is about 40 nm on the average. The photoluminescence (PL) spectra of the as-prepared Cu 0.45 Mn 0.55 O 2 nanostructures at room temperature exhibits prominent emission bands located in red–violet spectral region. Moreover, magnetic investigations revealed the weak ferromagnetic behavior of the as-prepared Cu 0.45 Mn 0.55 O 2 nanoflowers and reported for the first time using vibrating sample magnetometer (VSM).

FCC Superlattice Packing of Faceted Silver Nanocrystals

1997 ◽  
Vol 3 (S2) ◽  
pp. 403-404
Author(s):  
S.A. Harfenist ◽  
Z.L. Wang ◽  
M.M. Alvarez ◽  
I. Vezmar ◽  
R.L. Whetten
Keyword(s):  
Three Dimensional ◽  
Self Assembled Monolayers ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Core Diameter ◽  
Truncated Octahedron ◽  
Assembled Monolayers ◽  
High Resolution Tem ◽  
Orientational Ordering ◽  
Atomic Lattices

The ordering of size selected nanocrystaline particles into large, well ordered supercrystals has been under recent study. Here we describe the ordering of silver nanocrystals, of core diameter ca. 4.5nm, passivated with alkythiolate self-assembled monolayers. The faceted nanocrystals are found to size selectively condense into ordered supercrystals with edge lengths on the order of 0.1 to 0.5 microns. Further, evidence has been found in High Resolution TEM micrographs of packed monolayers of these same nanocrystals implying an orientational ordering of the silver nanocrystals’ atomic lattices within and co-aligning with the supercrystal’s “superlattice”. A three dimensional model using a truncated octahedron for the nanocrystal core morphology is constructed from this evidence into an FCC superlattice which fits the remaining experimental observations.Micrographs of the same region of a nanocrystal Ag supercrystal (NCASX) are shown in figure 1 under differing defocus conditions.

scholarly journals Two-dimensional characterization of three-dimensional nanostructures of magnetic bubbles in Fe3Sn2

2020 ◽  
Author(s):  
Jin Tang ◽  
Yaodong Wu ◽  
Lingyao Kong ◽  
Weiwei Wang ◽  
Yutao Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Microscopy Imaging ◽  
Magnetic Structures ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
High Resolution Tem ◽  
Lorentz Transmission Electron Microscopy

Abstract We report differential phase contrast scanning transmission electron microscopy (TEM) of nanoscale magnetic objects in Kagome ferromagnet Fe3Sn2 nanostructures. This technique can directly detect the deflection angle of a focused electron beam, thus allowing clear identification of the real magnetic structures of two magnetic objects including three-ring and complex arch-shaped vortices in Fe3Sn2 by Lorentz transmission electron microscopy imaging. Numerical calculations based on real material-specific parameters well reproduced the experimental results, showing that the magnetic objects can be attributed to integral magnetizations of two types of complex three-dimensional (3D) magnetic bubbles with depth-modulated spin twisting. Magnetic configurations obtained using the high-resolution TEM are generally considered as two-dimensional (2D) magnetic objects previously. Our results imply the importance of the integral magnetizations of underestimated 3D magnetic structures in 2D TEM magnetic characterizations.

CARBON NANOTUBES/GRAPHENE THREE-DIMENSIONAL NETWORKS ARCHITECTURE LOADING WITH Ni AND ITS ADSORPTION PROPERTIES

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450019 ◽  
Author(s):  
BIN ZENG ◽  
YOUXIN LUO ◽  
QIYUAN LIU ◽  
WUJUN ZENG
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Three Dimensional ◽  
Ni Nanoparticles ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
3D Network ◽  
First Time

The composite of carbon nanotubes/graphene networks loaded- Ni (CNTs/GR- Ni ) were successfully synthesized by spray drying and post-calcinating method for the first time. The synthesized products were systematically studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The result showed the hybrid of CNTs and graphene composed the 3D network structure and Ni nanoparticles were attaching on their surface. Adsorption performance evidenced that the obtained nanocomposite possessed high adsorption efficiency and excellent separation property.

Quantification of Inter-particle Spacing Caused by Thiol Self-Assembled Monolayers Using Transmission Electron Microscopy

Plasmonics ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 743-753
Author(s):  
Jairo P. Oliveira ◽  
Adilson R. Prado ◽  
Wanderson J. Keijok ◽  
Rafaela S. Valotto ◽  
André R. Silva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembled Monolayers ◽  
Particle Spacing ◽  
Transmission Electron ◽  
Assembled Monolayers ◽  
Self Assembled

Improved Microchip Design and Application for In Situ Transmission Electron Microscopy of Macromolecules

2013 ◽  
Vol 20 (2) ◽  
pp. 338-345 ◽  
Author(s):  
Madeline J Dukes ◽  
Rebecca Thomas ◽  
John Damiano ◽  
Kate L Klein ◽  
Sharavanan Balasubramaniam ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Resonance Imaging ◽  
Microscopy Imaging ◽  
Fundamental Properties ◽  
Local Environments ◽  
Transmission Electron ◽  
Magnetic Resonance Imaging Contrast

AbstractUnderstanding the fundamental properties of macromolecules has enhanced the development of emerging technologies used to improve biomedical research. Currently, there is a critical need for innovative platforms that can illuminate the function of biomedical reagents in a native environment. To address this need, we have developed an in situ approach to visualize the dynamic behavior of biomedically relevant macromolecules at the nanoscale. Newly designed silicon nitride devices containing integrated “microwells” were used to enclose active macromolecular specimens in liquid for transmission electron microscopy imaging purposes.We were able to successfully examine novel magnetic resonance imaging contrast reagents, micelle suspensions, liposome carrier vehicles, and transcribing viral assemblies. With each specimen tested, the integrated microwells adequately maintained macromolecules in discrete local environments while enabling thin liquid layers to be produced.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Simulation of three Dimensional Defect Images in Transmission Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 470-471
Author(s):  
W. D. Cooper ◽  
C. S. Hartley ◽  
J. J. Hren
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Crystalline Lattice ◽  
Continuum Models ◽  
Thin Foils ◽  
Transmission Electron ◽  
Microscope Images ◽  
General Computer Program ◽  
General Computer

Interpretation of electron microscope images of crystalline lattice defects can be greatly aided by computer simulation of theoretical contrast from continuum models of such defects in thin foils. Several computer programs exist at the present time, but none are sufficiently general to permit their use as an aid in the identification of the range of defect types encountered in electron microscopy. This paper presents progress in the development of a more general computer program for this purpose which eliminates a number of restrictions contained in other programs. In particular, the program permits a variety of foil geometries and defect types to be simulated.The conventional approximation of non-interacting columns is employed for evaluation of the two-beam dynamical scattering equations by a piecewise solution of the Howie-Whelan equations.

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