scholarly journals Towards an Understanding of Crystallization by Attachment

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 463
Author(s):  
Haihua Pan ◽  
Ruikang Tang
Keyword(s):  
Capillary Condensation ◽  
Force Measurements ◽  
Force Microscopy ◽  
Physical Conditions ◽  
Driving Mechanisms ◽  
Atomic Force ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Hydration Layers

Crystallization via particle attachment was used in a unified model for both classical and non-classical crystallization pathways, which have been widely observed in biomimetic mineralization and geological fields. However, much remains unknown about the detailed processes and driving mechanisms for the attachment. Here, we take calcite crystal as a model mineral to investigate the detailed attachment process using in situ Atomic Force Microscopy (AFM) force measurements and molecular dynamics simulations. The results show that hydration layers hinder the attachment; however, in supersaturated solutions, ionic bridges are formed between crystal gaps as a result of capillary condensation, which might enhance the aggregation of calcite crystals. These findings provide a more detailed understanding of the crystal attachment, which is of vital importance for a better understanding of mineral formation under biological and geological environments with a wide range of chemical and physical conditions.

scholarly journals Nucleation and Growth of Supported Metal Clusters at Defect Sites on Mgo and NaCl (001) Surfaces: The Cases of Pd and Ag

1999 ◽  
Vol 570 ◽  
Author(s):  
J. A. Venables ◽  
G. Haas ◽  
H. Brune ◽  
J.H. Harding
Keyword(s):  
Deposition Temperature ◽  
Metal Clusters ◽  
Variable Temperature ◽  
Nucleation And Growth ◽  
Force Microscopy ◽  
Atomic Force ◽  
Defect Sites ◽  
Wide Range ◽  
Adsorption Surface

ABSTRACTNucleation and growth of metal clusters at defect sites is discussed in terms of rate equation models, which are applied to the cases of Pd and Ag on MgO(001) and NaCl(001) surfaces. Pd/MgO has been studied experimentally by variable temperature atomic force microscopy (AFM). The island density of Pd on Ar-cleaved surfaces was determined in-situ by AFM for a wide range of deposition temperature and flux, and stays constant over a remarkably wide range of parameters; for a particular flux, this plateau extends from 200 K ≤ T ≤ 600 K, but at higher temperatures the density decreases. The range of energies for defect trapping, adsorption, surface diffusion and pair binding are deduced, and compared with earlier data for Ag on NaCl, and with recent calculations for these metals on both NaCl and MgO

Effect of pH on ceria–silica interactions during chemical mechanical polishing

2005 ◽  
Vol 20 (5) ◽  
pp. 1139-1145 ◽  
Author(s):  
Jeremiah T. Abiade ◽  
Wonseop Choi ◽  
Rajiv K. Singh
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Force Measurements ◽  
X Ray ◽  
Force Microscopy ◽  
Substrate Interaction ◽  
Atomic Force ◽  
Silica Removal

To understand the ceria–silica chemical mechanical polishing (CMP) mechanisms, we studied the effect of ceria slurry pH on silica removal and surface morphology. Also, in situ friction force measurements were conducted. After polishing; atomic force microscopy, x-ray photoelectron spectroscopy, and scanning electron microscopy were used to quantify the extent of the particle–substrate interaction during CMP. Our results indicate the silica removal by ceria slurries is strongly pH dependent, with the maximum occurring near the isoelectric point of the ceria slurry.

Low-Cost Nanomanipulator for In Situ Experiments in a SEM

2006 ◽  
Vol 12 (4) ◽  
pp. 311-316 ◽  
Author(s):  
Denise Nakabayashi ◽  
Paulo C. Silva ◽  
Juan C. González ◽  
Varlei Rodrigues ◽  
Daniel Ugarte
Keyword(s):  
Low Cost ◽  
Force Microscopy ◽  
Atomic Force ◽  
Manipulation System ◽  
Wide Range ◽  
In Situ Experiments ◽  
Plate Spring ◽  
Spring Mechanism ◽  
Physical Manipulation

Here, we describe the development of an inexpensive and versatile manipulation system for in situ experiments in a field emission scanning electron microscope based on a parallel-guiding plate-spring mechanism and low cost materials. The system has been tested for a wide range of applications, such as collecting, moving, and positioning particles, fabricating atomic force microscopy tips based on carbon nanotubes, and characterizing individual nanobjects. The nanomanipulation results demonstrate that there are many opportunities for the use of physical manipulation in the bottom-up approach to fabrication of nanodevices.

Building two-dimensional materials one row at a time: Avoiding the nucleation barrier

Science ◽  
2018 ◽  
Vol 362 (6419) ◽  
pp. 1135-1139 ◽  
Author(s):  
Jiajun Chen ◽  
Enbo Zhu ◽  
Juan Liu ◽  
Shuai Zhang ◽  
Zhaoyang Lin ◽  
...  
Keyword(s):  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Free Energy Barrier ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Nucleation Barrier ◽  
Atomic Force ◽  
Wide Range ◽  
Two Dimensional Materials ◽  
Dynamics Simulations

Assembly of two-dimensional (2D) molecular arrays on surfaces produces a wide range of architectural motifs exhibiting unique properties, but little attention has been given to the mechanism by which they nucleate. Using peptides selected for their binding affinity to molybdenum disulfide, we investigated nucleation of 2D arrays by molecularly resolved in situ atomic force microscopy and compared our results to molecular dynamics simulations. The arrays assembled one row at a time, and the nuclei were ordered from the earliest stages and formed without a free energy barrier or a critical size. The results verify long-standing but unproven predictions of classical nucleation theory in one dimension while revealing key interactions underlying 2D assembly.

scholarly journals In situ AFM visualization of Li–O2 battery discharge products during redox cycling in an atmospherically controlled sample cell

2019 ◽  
Vol 10 ◽  
pp. 930-940 ◽  
Author(s):  
Kumar Virwani ◽  
Younes Ansari ◽  
Khanh Nguyen ◽  
Francisco José Alía Moreno-Ortiz ◽  
Jangwoo Kim ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Double Layers ◽  
In Situ Observation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Highly Sensitive ◽  
Wide Range ◽  
Battery Discharge ◽  
The Impact

The in situ observation of electrochemical reactions is challenging due to a constantly changing electrode surface under highly sensitive conditions. This study reports the development of an in situ atomic force microscopy (AFM) technique for electrochemical systems, including the design, fabrication, and successful performance of a sealed AFM cell operating in a controlled atmosphere. Documentation of reversible physical processes on the cathode surface was performed on the example of a highly reactive lithium–oxygen battery system at different water concentrations in the solvent. The AFM data collected during the discharge–recharge cycles correlated well with the simultaneously recorded electrochemical data. We were able to capture the formation of discharge products from correlated electrical and topographical channels and measure the impact of the presence of water. The cell design permitted acquisition of electrochemical impedance spectroscopy, contributing information about electrical double layers under the system’s controlled environment. This characterization method can be applied to a wide range of reactive surfaces undergoing transformations under carefully controlled conditions.

scholarly journals Ultrafine metal-polymer catalysts based on polyconjugated systems for Fisher–Tropsch synthesis

2020 ◽  
Vol 92 (6) ◽  
pp. 977-984
Author(s):  
Mayya V. Kulikova ◽  
Albert B. Kulikov ◽  
Alexey E. Kuz’min ◽  
Anton L. Maximov
Keyword(s):  
Tropsch Synthesis ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
Force Microscopy ◽  
Composite Catalysts ◽  
Fe Catalyst ◽  
Atomic Force ◽  
And Function ◽  
Metal Polymer

AbstractFor previously studied Fischer–Tropsch nanosized Fe catalyst slurries, polymer compounds with or without polyconjugating structures are used as precursors to form the catalyst nanomatrix in situ, and several catalytic experiments and X-ray diffraction and atomic force microscopy measurements are performed. The important and different roles of the paraffin molecules in the slurry medium in the formation and function of composite catalysts with the two types of aforementioned polymer matrices are revealed. In the case of the polyconjugated polymers, the alkanes in the medium are “weakly” coordinated with the metal-polymer composites, which does not affect the effectiveness of the polyconjugated polymers. Otherwise, alkane molecules form a “tight” surface layer around the composite particles, which create transport complications for the reagents and products of Fischer-Tropsch synthesis and, in some cases, can change the course of the in situ catalyst formation.

Atomic force microscopy of in situ deformed nickel thin films

1999 ◽  
Vol 353 (1-2) ◽  
pp. 194-200 ◽  
Author(s):  
C. Coupeau ◽  
J.F. Naud ◽  
F. Cleymand ◽  
P. Goudeau ◽  
J. Grilhé
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Nickel Thin Films ◽  
Atomic Force
Sign in / Sign up

Export Citation Format

Share Document