Jimmy Wang

An x-ray scattering study of laterally modulated structures: the example of diblock copolymers

A study of the specular and off-specular (diffuse) x-ray scattering of a diblock copolymer is presented. In the ordered state the surface of the diblock copolymer is covered with islands. It is shown that the periodicity in the ordered state in the direction normal to the surface in a specular scan differs from the periodicity in the same direction observed in an off-specular scan. This result is explained by an analytical calculation of the differential cross section. The introduction of the statistical properties of the island distribution allows a complete analytical calculation of the transverse scans yielding the determination of the mean distance between the islands and the average size of an island.

Mass measurements of

J. A. Clark1,2,3, A. Parikh1, F. Buchinger4, J. A. Caggiano1, J. E. Crawford4, C. Deibel1, J. P. Greene3, S. Gulick4, J. C. Hardy5, A. A. Hecht3,6, J. K. P. Lee4, A. F. Levand3, R. Lewis1, B. F. Lundgren3, P. D. Parker1, G. Savard3, N. D. Scielzo3, K. S. Sharma2, I. Tanihata3, W. Trimble3, J. C. Wang2,3, Y. Wang2,3, C. Wrede1, and Z. Zhou3 1Wright Nuclear Structure Laboratory, Yale University, New Haven, CT 06520, USA 2Department of Physics and Astronomy, University of Manitob a, Winnipeg, MB R3T 2N2, Canada 3Physics Division, Argonne National Laboratory, Argonne, I L 60439, USA 4 Department of Physics, McGill University, Montreal, PQ H3A 2T8, Canada 5Cyclotron Institute, Texas A&M University, College Statio n, TX 77843-3366, USA 6Department of Chemistry, University of Maryland, College P ark, MD 20742, USA