G. Ramanath Professor of Materials Science and Engineering Office: 111 Materials Research Center Phone: 518.276.6844 E-mail: Ramanath [at] rpi [dot] edu URL: www.rpi.edu/dept/materials/GR

[ Curriculum Vita | Publication list ]

Functional nanostructures and thin films for device and energy applications:
Directed synthesis, assembly, modification and atomic-level engineering of properties

Professor Ramanath received his Ph.D. in Materials Science and Engineering from the University of Illinois-Urbana in 1997. His doctoral work won him a Materials Research Society Graduate Student Award (now known as the Gold Award). He obtained his B.Tech. in Metallurgical Engineering from the IIT, Madras, India, and his M.S. in Materials Science and Engineering from the University of Cincinnati. He was a staff member at Novellus Systems, CA, and a Visiting Scientist at the Physics Department of Linköping University, Sweden, before he joined the Rensselaer faculty in Fall 1998 as an Assistant Professor. He became a tenured Associate Professor in 2003, and was promoted to full Professor in 2006. He is a recipient of a Early CAREER Award from the National Science Foundation (2000), Prof. Bergmann Memorial Young Scientist Award from the US-Israel Binational Science Foundation (2003), and is a co-recipient of IBM Research Partnership Award (1999-2006), Best paper award IEEE Nano (Hong Kong, 2007). He has been a Visiting Professor at the International Center for Young Scientists, Tsukuba, Japan (summer 2004), the Nanoscale Science Department at the Max Planck Institute für Festkörperforschung, Stuttgart, Germany as an Alexander von Humboldt Fellow (2004-2005), and the Indian Institute of Science, Bangalore, India (summer 2006). He is an Associate Editor of IEEE Transactions on Nanotechnology since October 2003, and serves on the editorial advisory board of the Journal of Experimental Nanoscience and the The Open Materials Science Journal.

Professor Ramanath's current research interests are in the areas of synthesis, assembly, and characterization of nanostructures and thin films, with emphasis on exploring new materials and architectures for fabricating future nanodevices for computing, energy generation and management, and understanding the relationships between atomic-level structure and chemistry, and properties. Below are synopses of current topics being pursued in his group.

• Directed synthesis and assembly of nanoscopic building blocks and heterostructures: The underlying theme here is to devise strategies to synthesize nanostructures of desired dimensionalities by scalable methods, and construct larger scale architectures in a controllable fashion by combining chemical and/or physical guidance (molecular templating, lithography, ion irradiation, microwave stimulation etc.) with self-assembly. We study the molecular/atomic-level mechanisms by utilizing a combination of multiple electron microscopy, diffraction and spectroscopy techniques. We probe and understand the relationships between structure, chemistry with electrical, magnetic, thermoelectric and mechanical properties, and sensory responses. Examples of structures being investigated include oriented nanotube architectures, branched nanowires, nanorods, and porous networks, one- and two-dimensional assemblies of high-coercivity nanomagnets, core-shell and branched structures of high-figure of merit thermoelectrics, interpenetrating proximal nanowire networks of high- and low-bandgap seminconductors for solar cell applications.
• Molecularly tailored interfaces and thin films: The goal of this thrust is to understand processing-stability-property relationships and atomistic/molecular-level mechanisms of thin film interfacial reactions and phase formation during growth (e.g., sputter-deposition, CVD, self-assembly) and post-deposition treatments and relate them to key film and interfacial properties. Topics explored in the past include thin film microstructure evolution and interfacial reactions. The current focus is on investigating the use of self-assembled molecular nanolayers at the interfaces of thin films and nanostructured assemblies as chemical isolators, physical spacers, and adhesion enhancers, and creating molecularly-passivated materials. We are integrating diffusion-inhibiting and adhesion-enhancing molecules with precursors of porous materials to create high interface integrity materials for use as low-k dielectrics in devices. Our studies include quantitative measurements of diffusion barrier properties, mechanical toughness, coverage, electrical characteristics, reliability, and thermal stability of metal-dielectric interfaces and molecularly-tailored porous materials. We are also exploring strategies to directly reduce metal salts directly using termini of molecular assemblies incorporated inside porous materials to obtain a high loading of nanoparticles of controlled shapes/sizes in porous matrices to add a new component to our directed synthesis efforts.
• Processing and microanalytical techniques: We are interested in, and adept at, synergistically combining and devising new multiple processing approaches for thin film/nanostructure synthesis, and exploiting multiple microanalysis techniques to capture key features of atomistic/molecular-level phenomena. We use combinations of CVD, PVD, directed self-assembly (from wet-chemical and vapor-phase fluxes), nanofabrication (e.g., lithography, etching), ion-irradiation, microwaves, and post-deposition annealing in vacuum/controlled gas ambients. Our growing toolbox of microanalytical techniques include electron microscopy (conventional and high resolution TEM, diffraction, SEM), related spatially resolved X-ray and electron spectroscopy techniques, XRD, various spectroscopies (e.g., RBS, XPS, AES, SIMS, EDX, IR, UV-visible), in situ electrical measurements during deposition and annealing, 4-point bend adhesion testing and electrical device testing (I-V, C-V, TVS, etc.).

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Department of Materials Science & Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
Phone: 518.276.6372 Fax: 518.276.8554