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GANAPATHIRAMAN RAMANATH

persons photo Title(s): Professor
Department: Materials Science and Engineering
Website: http://www.rpi.edu/dept/materials/GR/
Email: ramanath[at]rpi[dot]edu
Phone: (518) 276-6844
Fax: (518) 276-8554
Postal Mail: Rensselaer Polytechnic Institute, 110-8th Street
(111 Materials Research Center) Troy, NY 12180

Career Highlights

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. 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 as an Assistant Professor in Fall 1998. He became a tenured Associate Professor in 2003, and was promoted to Full Professor in 2006.

Professor Ramanath is a recipient of a CAREER Award from the National Science Foundation (2000), Prof. Bergmann Memorial Young Scientist Award from the US-Israel Binational Science Foundation (2003), and a co-recipient of IBM Research Partnership Award (1999-2006). He has held Visiting Professorships 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 (2004-05), 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.

Research Areas

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.

Thin film science and molecularly tailored inorganic materials and interfaces

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. My current focus is on investigating the use of self-assembled molecular nanolayers (SAMs) at the interfaces of thin films and nanostructured assemblies as chemical isolators, physical spacers, and adhesion enhancers. Our studies include quantitative measurements of diffusion barrier properties, mechanical toughness, coverage, electrical characteristics, reliability, and thermal stability of ~1-5 nm-thick SAMs with different molecular termini and lengths at metal-dielectric interfaces. We are integrating diffusion-inhibiting and adhesion-enhancing molecular termini with precursors of porous materials before gelation to create high interface integrity materials for use as low-k dielectrics in devices. We are also exploring strategies to directly reduce metal salts using molecular termini of SAMs 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.).

Selected Publications

Nanostructures synthesis, assembly and modification

  • Low-temperature templateless synthesis of single-crystal bismuth telluride nanorods, A. Purkayastha, F. Lupo, S. Kim, T. Borca-Tasciuc, G. Ramanath, Adv. Mater. 18, 496-500 (2006).
  • Molecularly-protected bismuth telluride nanoparticles: microemulsion synthesis, and thermoelectric transport properties, A. Purkayastha, P.G. Ganesan, A. Kumar, S.-Y. Kim, T. Borca-Tasciuc, G. Ramanath, Adv. Mater. 18, 2958-2963 (2006).
  • Monodisperse high magnetic coercivity silica-capped FePt nanoparticles of tunable size, composition and thermal stability from microemulsions, Q. Yan, A. Purkayastha, T. Kim, R. Kröger, A. Bose, G. Ramanath, Adv. Mater. 18, 2569–2573 (2006).
  • Electrical current-induced structural changes and chemical functionalization of carbon nanotubes, S. Agrawal, M. S. Raghuveer, R. Kröger, G. Ramanath, J. Appl. Phys. 100, 094314 (2006).
  • Microwave-assisted single-step functionalization and in-situ derivatization of carbon nanotubes with gold nanoparticles, M. S. Raghuveer, S. Agrawal, N. Bishop (undergrad), G. Ramanath, Chem. Mater. 18, 1390-1393 (2006).
  • Site-selective functionalization of carbon nanotubes, M.S. Raghuveer, A. Kumar, M.J. Frederick, G.P. Louie (high school teacher), P.G. Ganesan, G. Ramanath, Adv. Mater. 18, 547-552 (2006).
  • Wet-chemical templateless assembly of metal nanowires from nanoparticles, T. Maddanimath, A. Kumar, J. D’Arcy-Gall, P.G. Ganesan, K. Vijayamohanan, G. Ramanath, Chem. Comm. 11, 1435-37 (2005)
  • Hybrid microstructures from aligned carbon nanotubes and silica particles, S. Agrawal, A. Kumar, M.J. Frederick, G. Ramanath, Small 1 (8-9), 823-826 (2005) Coverpage feature
  • Nanomachining carbon nanotubes with ion beams, M.S. Raghuveer, P.G. Ganesan, J. Mabon, J. D’Arcy-Gall, G. Ramanath, Appl. Phys. Lett. 84(22), 4484-4486 (2004)
  • Exclusive horizontal growth of aligned carbon nanotubes with controlled site-selectivity and length, A. Cao, R. Baskaran, M.J. Frederick, P. M. Ajayan, K. Turner, G. Ramanath, Adv. Mater. 15(13), 1105 (2003)
  • Organized assemblies of carbon nanotubes, B.Q. Wei, R. Vajtai, Y. Jung, J. Ward, Y. Zhang, G. Ramanath, P. Ajayan, Nature 416, 495 (2002)

  • Molecularly modified thin films and interfaces

  • Suppression of chemical and electrical instabilities in mesoporous silica films by molecular capping, A.P. Singh, D. Gandhi, E. Lipp, M. Eizenberg, G. Ramanath, J. Appl. Phys. 100, 114504 (2006)
  • Surface oxide reduction and bilayer molecular assembly of a thiol terminated organosilane on Cu, P.G. Ganesan, A. Kumar, G. Ramanath, Appl. Phys. Lett. 87(1), 011905 (2005)
  • Diffusion barrier properties of carboxyl- and amine-terminated molecular nanolayers, P.G. Ganesan, A.P. Singh, and G. Ramanath, Appl. Phys. Lett. 85(4), 579-581 (2004)
  • Interfacial phase formation in Cu-Mg alloy films on SiO2, M.J. Frederick and G. Ramanath, J. Appl. Phys. 95(6), 3202-3205 (2004)
  • Self assembled nanolayers as adhesion enhancers and diffusion barriers, G. Ramanath, G. Cui, M. Stukowski, X. Guo, P. G. Ganesan, A.V. Ellis, K. Vijayamohanan, P. Doppelt, M. Lane, Appl. Phys. Lett. 83(2), 383 (2003).
  • Polyelectrolyte nanolayers as diffusion barriers for Cu metallization, P.G. Ganesan, J. Gamba, A. Ellis, R.S. Kane, G. Ramanath, Appl. Phys. Lett. 83, 3302 (2003).
  • Self assembled near-zero thickness molecular layers as diffusion barriers for Cu metallization, A. Krishnamoorthy, K. Chanda, S. P. Murarka, J. G. Ryan and G. Ramanath, Appl. Phys. Lett. 78(17), 2467 (2001).

Professional Appointments

2006-   Professor, Materials Science and Engineering, Rensselaer
Polytechnic Institute
2003-2006 Associate Professor, Materials Science and Engineering, Rensselaer
Polytechnic Institute
1998-2003 Assistant Professor, Materials Science and Engineering, Rensselaer
Polytechnic Institute
2003- Associate Editor, IEEE Transactions on Nanotechnology
Summer '06 Visiting Professor of Materials Engineering, Indian Institute of Science, Bangalore, India
2004-05 Alexander von Humboldt Fellow, Max Planck Institute for Solids State Research, Stuttgart, Germany
Summer '04 Visiting Professor, International Center for Young Scientists, Tsukuba, Japan
1998 Visiting Scientist, Physics Department, Linköping University, Sweden
1997-1998 Senior Engineer, Novellus Systems, Inc., San Jose, CA

Professional Preparation

University of Illinois at Urbana-Champaign   Materials Science and Engineering Ph.D. 1997
University of Cincinnati Materials Science and Engineering M.S. 1993
Indian Institute of Technology, Madras Metallurgical Engineering B. Tech 1990

Common Mis-spellings

Ramnath Ramanth