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Title: Understanding and Controlling Nanoscale Crystal Growth Using Mechanical Forces

Authors:
;
Publication Date:
Research Org.:
University of Michigan
Sponsoring Org.:
USDOE
OSTI Identifier:
1160219
Report Number(s):
Final01
DOE Contract Number:
SC0004927
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English

Citation Formats

Hart, A. John, and Bedewy, Mostafa. Understanding and Controlling Nanoscale Crystal Growth Using Mechanical Forces. United States: N. p., 2014. Web. doi:10.2172/1160219.
Hart, A. John, & Bedewy, Mostafa. Understanding and Controlling Nanoscale Crystal Growth Using Mechanical Forces. United States. doi:10.2172/1160219.
Hart, A. John, and Bedewy, Mostafa. Wed . "Understanding and Controlling Nanoscale Crystal Growth Using Mechanical Forces". United States. doi:10.2172/1160219. https://www.osti.gov/servlets/purl/1160219.
@article{osti_1160219,
title = {Understanding and Controlling Nanoscale Crystal Growth Using Mechanical Forces},
author = {Hart, A. John and Bedewy, Mostafa},
abstractNote = {},
doi = {10.2172/1160219},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Oct 22 00:00:00 EDT 2014},
month = {Wed Oct 22 00:00:00 EDT 2014}
}

Technical Report:

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  • In this program, we developed new theoretical and experimental insights into understanding the relationships among fundamental universality and scaling phenomena, the solid-state physical and mechanical properties of materials, and the volume plasmon energy as measured by electron energy-loss spectroscopy (EELS). Particular achievements in these areas are summarized as follows: (i) Using a previously proposed physical model based on the universal binding-energy relation (UBER), we established close phenomenological connections regarding the influence of the valence electrons in materials on the longitudinal plasma oscillations (plasmons) and various solid-state properties such as the optical constants (including absorption and dispersion), elastic constants, cohesive energy,more » etc. (ii) We found that carbon materials, e.g., diamond, graphite, diamond-like carbons, hydrogenated and amorphous carbon films, exhibit strong correlations in density vs. Ep (or maximum of the volume plasmon peak) and density vs. hardness, both from available experimental data and ab initio DFT calculations. This allowed us to derive a three-dimensional relationship between hardness and the plasmon energy, that can be used to determine experimentally both hardness and density of carbon materials based on measurements of the plasmon peak position. (iii) As major experimental accomplishments, we demonstrated the possibility of in-situ monitoring of changes in the physical properties of materials with conditions, e.g., temperature, and we also applied a new plasmon ratio-imaging technique to map multiple physical properties of materials, such as the elastic moduli, cohesive energy and bonding electron density, with a sub-nanometer lateral resolution. This presents new capability for understanding material behavior. (iv) Lastly, we demonstrated a new physical phenomenon - electron-beam trapping, or electron tweezers - of a solid metal nanoparticle inside a liquid metal. This phenomenon is analogous to that of optical trapping of solid microparticles in solution known as "optical tweezers", which is currently being used to manipulate molecules and inorganic materials in a variety of nanotechnology applications.« less
  • The purposes for which this grant was provided were specifically (1) to construct a tandem instrument that combined a low energy electron microscope (LEEM) with an ion beam source capably of irradiating a sample during observation of the surface using LEEM; and (2) to employ the new machine to whatever degree possible to observe the evolution of clean crystal surfaces during ion beam irradiation. A principal motivation was to investigate the fundamental behavior of radiation damage under circumstances for which the damage can be observed directly in real time as it occurs. A second main motivation was to create tunablemore » perturbations of the defect (adatom and advacancy) equilibrium on clean crystal planes and in this way explore the fundamental kinetics of surface behavior that enters into numerous phenomena of interest to DOE including surface erosion, catalysis, and the damage to crystals caused by impacts of energetic particles. The funding has been employed to successfully pursue all the original goals, and additional opportunities that developed as a result of discoveries made in this research.« less
  • Most of the low-temperature reactions that are geochemically important involve a bonded atom or molecule that is replaced with another. We probe these reactions at the most fundamental level in order to establish a model to predict rates for the wide range of reactions that cannot be experimentally studied.
  • The feasibility of developing a position-sensitive CdTe detector array for astronomical observations in the hard X-ray, soft gamma ray region is demonstrated. In principle, it was possible to improve the resolution capability for imaging measurements in this region by orders of magnitude over what is now possible through the use of CdTe detector arrays. The objective was to show that CdTe crystals of the quality, size and uniformity required for this application can be obtained with a new high pressure growth technique. The approach was to fabricate, characterize and analyze a 100 element square array and several single-element detectors usingmore » crystals from the new growth process. Results show that detectors fabricated from transversely sliced, 7 cm diameter wafers of CdTe exhibit efficient counting capability and a high degree of uniformity over their entire areas. A 100 element square array of 1 sq mm detectors was fabricated and operated.« less