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Background removal is an important step in the quantitative analysis of electron energy-loss structure. Existing methods usually require an energy-loss region outside the fine structure in order to estimate the background. This paper describes a method for signal-from-background separation that is based on subspace division. The linear space is divided into two subspaces. The signal is recovered from a linear subspace containing no background information, and the other subspace containing the background is discarded. This method does not rely on any signal outside the energy-loss range of interest and should be very helpful for multiple linear least-squares (MLLS) regression analysis on experimental signals with little or no available smooth pre-edge region or with overlapping pre-edge features. Use of the algorithm is demonstrated with several practical applications, including closely overlapping core-loss spectra and zero-loss peak removal. Tests based on experimental data indicate that the algorithm has similar or better performance relative to conventional pre-edge power-law fitting methods in applications such as MLLS regression for electron energy-loss near-edge structure.

Display Omitted Highly crystalline BaTiO3 was integrated on Si using molecular beam epitaxy.Electro-optic response was evaluated for a-axis, c-axis, and mixed films.Increased a-axis fraction correlated with increased electro-optic response.Post-deposition oxygen anneal improved crystallinity and reduced leakage current. High-quality epitaxial BaTiO3 (BTO) on Si has emerged as a highly promising material for future electro-optic (EO) devices based on BTO's large effective Pockels coefficient. We report on the EO response of BTO films deposited on Si by molecular beam epitaxy (MBE), and characterize the structure of these films by reflection high-energy electron diffraction and X-ray diffraction. O2 rapid thermal anneal at 600?C for 30min ensures full oxidation of BTO for minimal leakage current with minimal change in crystalline structure.