welcome to Elaine DiMasi's office

research | facilities | publications and CV | contact information | more

		Research The papers and sample boxes at the tops of the piles are all related to natural materials with complicated structures on many length scales, leading to special material properties. Evidently these materials are studied primarily by x-ray scattering techniques at the National Synchrotron Light Source at BNL.
		There are some Biominerals here. Biominerals such as these pieces of Red Abalone shell are constructed of ordinary minerals assembled in extraordinary ways: in this case, calcium carbonate in both aragonitic and calcitic forms, with a detailed hierarchical nanostructure that incorporates very small amounts of organic molecules. Seashells are much tougher than inorganic calcium carbonate minerals, and it is still unclear exactly how the growth of these structures is controlled. Since biominerals often nucleate at interfaces, surface-sensitive synchrotron x-ray scattering is a choice tool to study these structures. We are also using synchrotron microbeam x-ray diffraction to characterize the micron-scale substructures formed by these crystals. (Read more about Elaine's biomineral projects.) News! Streaming video of NSLS UEC workshop, May 2005 "Synchrotron Imaging of Nanoscale Structure in Biominerals" There are some little bits of Clay. Clays are very neat materials! Just think about what is happening in the process of making a clay pot. Under the pressure of the potter's fingers, the clay flows like a fluid; then stays put, like a solid. If you've ever done this, you also know how crucial it is to have the right amount of water in the clay. The complex properties of clay are due to interactions between its plate-shaped particles, strongly controlled by the hydration state. Read more. This looks like a liquid surface. As you gaze into the Langmuir trough, you perceive that the surface of the liquid quite possibly has a structure distinct from that in the bulk, due to the constraints imposed on the atoms at the interface. This can lead to surface-induced order and even stabilize surface phases in the case of liquid metal alloy systems. A recent highlight: Attractive Interactions and Pairing in Liquid Bi-In. There's a whole file cabinet full of liquid metal stuff in this office. (Well, there used to be, until I shipped the papers to a graduate student in Iran.) But you also realize that the liquid surface can serve as a template, for example allowing one to study organic molecules like membrane proteins under physically relevant conditions. The bubbly liquid you're looking at now is actually a calcium carbonate subphase, and crystals are nucleating at the surface. The study of mineral nucleation at Langmuir films is part of Elaine's biomineral research program.

		Facilities Elaine shares responsibility for support of NSLS x-ray diffraction and scattering beamlines, especially grazing incidence scattering, liquid surfaces, microbeam diffraction, and their applications in biophyics and nanotechnology. See the NSLS website for an overview of facilities available to outside users, including BNL's Center for Functional Nanomaterials.
		New GISAXS Beamlines Improved capabilites for studying thin films and surfaces are under development, and we welcome potential users' input. Microbeam Diffraction and Imaging A new undulator-based beamline for microbeam studies is under construction at X13B. Interested users, contact us. Beamlines X22A,B,C The BNL Physics Department X-ray Scattering Group operates three beamlines at the National Synchrotron Light Source. Elaine DiMasi previously served as Local Contact for beamline X22B, responsible for outside users, scheduling, and maintenance of the liquid surface spectrometer.The group is also actively involved in similar programs at the CMC-CAT beamlines at the Advanced Photon Source. For more information please see the X-ray Group Homepage, or contact any current group member. Scientists within the X-ray Group and the NSLS reseach staff have created a Soft Condensed Matter working group, focussed on studies of liquids and soft matter at nanometer length scales. This research makes use of surface and microbeam x-ray techniques and AFM. See the SCMG homepage for more. Elaine is a member of the NSLS Beamtime Allocation Panel and has also served as secretary of the NSLS Users' Executive Committee. For information, see the NSLS website. For insiders: x22b | cmc instrumentation updates | materials studio user group | x6b listserver

		Publications, CV, and Contact Information Some favorite (representative!) publications are: Polymer-Controlled Growth Rate of an Amorphous Mineral Film Nucleated at a Fatty Acid Monolayer E. DiMasi, V. M. Patel, M. Sivakumar, M. G. Olszta, Y. P. Yang, and L. B. Gower, Langmuir 18 (2002) 8902. Pairing interactions and Gibbs Adsorption at the Liquid Bi-In Interface: Observations by Resonant X-ray Reflectivity E. DiMasi, H. Tostmann, B. M. Ocko, O. G. Shpyrko, P. Huber, P. S. Pershan, M. Deutsch, and L. E. Berman, Phys. Rev. Lett. 86 (2001) 1538. Surface Induced Order in Liquid Metal Alloys E. DiMasi and H. Tostmann, Synchrotron Radiation News 12 (1999) 41. Stability of Charge Density Waves under Continuous Variation of Bandfilling in LaTe2-xSbx E. DiMasi, B. Foran, M. C. Aronson and S. Lee, Phys. Rev. B 54 (1996) 1. Searching for more, you easily locate a handy, html-formatted complete publication list. Contact Elaine DiMasi directly for an up-to-date CV. National Synchrotron Light Source Department, Bldg. 725D Brookhaven National Laboratory Upton NY 11973-5000 Phone: +1 (631) 344-2211 Email: dimasi@bnl.gov