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Publication Citation: Elastic constants and dimensions of imprinted polymeric nanolines determined from Brillouin light scattering

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Author(s): Ward L. Johnson; Sudook A. Kim; Roy H. Geiss; Colm Flannery; Paul R. Heyliger; Christopher Soles; Wen-Li Wu; Chengqing C. Wang; Christopher M. Stafford; B D. Vogt;
Title: Elastic constants and dimensions of imprinted polymeric nanolines determined from Brillouin light scattering
Published: January 18, 2010
Abstract: Elastic constants and cross-sectional dimensions of imprinted nanolines of poly(methyl methacrylate) (PMMA) on silicon are determined nondestructively from finite-element inversion analysis of dispersion curves of hypersonic acoustic modes of these nanolines measured with Brillouin light scattering (BLS). The results for the cross-sectional dimensions, under the simplifying assumption of vertical sides and a semicircular top, are found to be consistent with dimensions determined from critical-dimension small-angle xray scattering (CD-SAXS) measurements. The elastic constants C_11 and C_44 are found to be, respectively, 11.6 % and 3.1 % lower than their corresponding values in bulk PMMA. This result is consistent with thickness-dependent changes in Young's modulus determined from quasi-static buckling measurements on PMMA films with lower molecular weights. This study provides the first evidence of size-dependent effects on hypersonic elastic properties of polymers.
Citation: Nanotechnology
Volume: 21
Issue: 7
Pages: pp. 1 - 8
Keywords: BLS; Brillouin light scattering; elastic constants; finite element analysis; nanoimprint lithography; nanolines; PMMA;
Research Areas: Characterization, Nanomaterials, Characterization, Nanometrology, and Nanoscale Measurements
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