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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 />

184

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