FY2010 - Oak Ridge National Laboratory
FY2010 - Oak Ridge National Laboratory
FY2010 - Oak Ridge National Laboratory
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Seed Money Fund—<br />
Center for Nanophase Materials Sciences<br />
We have devised a Monte Carlo method to simulate the segregation of the phase domains by considering<br />
several factors. The first is the thermodynamic energy of the coexisting phases, which depends on the<br />
temperature and the applied stress and is also a function of the local chemical composition. The second<br />
factor is the energy of the phase boundaries, which is expressed as the square of the gradient of the phase<br />
field variable. The strain energy is nonlocal whose range is the size of the phase domains; therefore, it is<br />
difficult to include in an efficient simulation. We approximate the strain energy by the surface-to-volume<br />
ratio of the phase domains. Because the presence of the domain boundaries releases the strain, the higher<br />
the surface-to-volume ratio, the lower the strain energy is. Adding these terms together, our Monte Carlo<br />
simulations show segregations of several different types of phase domains, which will be compared with<br />
experimental observations.<br />
05889<br />
Rapid Functional Recognition Imaging in Scanning Probe Microscopy<br />
Sergei V. Kalinin and Stephen Jesse<br />
Project Description<br />
We propose a scanning probe microscopy (SPM) data acquisition, processing, and control method for<br />
rapid quantitative mapping of local properties and functionality in inorganic, molecular, polymer, and<br />
biological systems. The method, further referred to as functional recognition imaging, is based on the<br />
rapid acquisition and automatic de-noising, classification, and interpretation of spectral, multimodal, or<br />
multispectral data sets (multidimensional data) at each spatial pixel. This recognition step substitutes for<br />
classical homodyne-based data processing or simple postprocessing of multidimensional data.<br />
Recognition data can be stored as an image, used as a feedback signal, or used as a trigger to control more<br />
complex microscope operations such as manipulation or communication. When successful, the project<br />
will open a direct pathway for rapid recognition imaging in all areas of nanoscience by providing a bridge<br />
between advanced computational and modeling capabilities and SPM data.<br />
Mission Relevance<br />
The proposed paradigm for functional imaging potentially allows revolutionizing the landscape of<br />
scanning probe microscopy by providing a reliable bridge between advanced modeling capabilities and<br />
experimental data that can be incorporated during in-line microscope operation. The recent DOE Grand<br />
Challenges and DOE workshop documents list the capability to probe and manipulate matter and<br />
information on the nanoscale as one of the key targets for DOE research, suggesting high relevance for<br />
energy-related fundamental research. The specific topic in this work—energy losses during mechanical<br />
tip-surface contact—are highly relevant to fundamental aspects of mechanical behavior and friction in<br />
spatially confined systems. Furthermore, methods for biological imaging and recognition are remaining a<br />
traditional priority for the <strong>National</strong> Institutes of Health. Recognition imaging microscopy offers an ideal<br />
pathway for this funding by providing a method to differentiate cells based on their phenotype. Hence,<br />
cancer and molecular imaging programs are a natural source of funding. Notably, the proposed algorithm<br />
can be potentially used in conjunction with other detected signals, including optical, mass-spectral, or<br />
microwave.<br />
Results and Accomplishments<br />
We have demonstrated the recognition spectroscopic imaging for rapid identification of biological,<br />
molecular, and atomic species in the SPM experiments. In this, the spectroscopic response (e.g., forcedistance<br />
curve or broadband excitation response) is acquired on a spatially resolved grid on the sample<br />
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