Materials Synthesis at ORNL

The Role of Synthesis in Materials Research

The number of known materials is vast, and is growing every year.  Only a small fraction of these materials are scientifically interesting or technologically important.  These ideas are compactly illustrated with “The Materials Pyramid.”  The width of the pyramid represents the number of materials, and the height of the pyramid represents the level of knowledge we possess about a certain material.  Thus at the base of the pyramid there are a vast number of materials about which we know little, and at the top there are a small number of materials about which we know a great deal.  In general, research at the bottom of the pyramid tends to be more fundamental, and at the top more applied.  In practice, important materials start off at the bottom of the pyramid and work their way upwards with time as they are studied more intensively. 

Materials synthesis is important at every level of the pyramid.  For example, at the base there is a lot of exploratory synthesis activity, and the newly discovered materials may not even exist in phase pure form.  As one moves up the pyramid, the materials improve in quality: the number of impurities is reduced, and often single crystals are grown for in-depth study.  ORNL synthesis programs are found at every level of the pyramid.


Transition metal oxide crystal being grown in an optical furnace.
Crystals of BaFe1.84Co0.16As2 grown from a flux.

Correlated Electron Materials. This program works on materials at the cutting edge of condensed matter physics, and the focus of the research is on phenomena that emerge from complex many-particle interactions. Phenomena such as unconventional superconductivity, multiferroic behavior, charge and orbital ordering, exotic magnetism, and the anomalous Hall effect are investigated. Both transition metal oxides and complex Zintl phases are studied. Transition metal oxides display an enormous variety of behavior (metals, insulators, all types of magnets, ferroelectrics, superconductors, etc.) and have an energy scale on the order of room temperature, so these materials are attractive for applications as well as fundamental studies. Zintl phases are intermetallic compounds in which different types of bonding (ionic and covalent) co-exist in the same material. These materials show great flexibility in bonding and tend to have open crystal structures. The magnetism is often highly unusual and the materials also often display “glassy” lattice dynamics, making these systems attractive for thermoelectric applications. Contact: David Mandrus.

Selected References:

  • A. D. Christianson, M. D. Lumsden, M. Angst, Z. Yamani, W. Tian, R. Jin, E. A. Payzant, S. E. Nagler, B. C. Sales, and D. Mandrus, “Three-Dimensional Magnetic Correlations in Multiferroic LuFe2O4,” Phys. Rev. Lett. 100(10), 107601 (2008).
  • A. S. Sefat, M. A. McGuire, B. C. Sales, R. Y. Jin, J. Y. Howe, and D. Mandrus, “Electronic Correlations in the Superconductor LaFeAsO0.89F0.11 with Low Carrier Density,” Phys. Rev. B 77 (17), 174503 (2008).
  • B. C. Sales, R. Jin, and D. Mandrus, “Orientation Dependence of the Anomalous Hall Fesistivity in Single Crystals of Yb14MnSb11,” Phys. Rev. B 77 (2), 024409 (2008).
  • A. S. Sefat, R. Jin, M. A. McGuire, B. C. Sales, D. J. Singh, and D. Mandrus, “Superconductivity at 22 K in Co-doped BaFe2As2 Crystals,” Physical Review Letters 101, 117004 (2008).
  • M. A. McGuire, A. D. Christianson, A. S. Sefat, B. C. Sales, M. D. Lumsden, R. Jin, E. A. Payzant, D. Mandrus, Y. Luan, V. Keppens, V. Varadarajan, J. W. Brill, R. P. Hermann, M. T. Sougrati, F. Grandjean, and G. J. Long, “Phase transitions in LaFeAsO: structural, magnetic, elastic, and transport properties, heat capacity and Mossbauer spectra,” Physical Review B 78, 094517 (2008).
Hemispherical gold nanoparticles grown on γ-A12O3

Vapor Phase Synthesis of Nanoparticles. This program uses physical vapor deposition to grow nanoparticles on bulk and thin-film support surfaces. Using this technique atomic metal species are generated by the sputtering of a high purity target using a conventional magnetron sputtering source. The atoms rain down onto a support material where they nucleate and grow into nanoparticles. The support powders are constantly agitated under the atomic rain exposing a new surface to the deposition flux thus coating the support material uniformly. The benefit of this approach is that nanoparticles can be grown on virtually any vacuum compatible material in a quick one-step manor thus greatly expanding the selection of support materials and this technique enables us to understand how the solution phase synthesis of supported metal clusters influences the properties of the support material since this is a solution free process. Contact: Gabriel M. Veith.


  • “Role of pH in the formation of structurally stable and catalytically active TiO2-supported gold catalysts”, Gabriel M. Veith, Andrew R. Lupini, and Nancy J. Dudney – In-press – Journal of Physical Chemistry C (2008).
  • “Thermal stability and catalytic activity of gold nanoparticles supported on silica”, Gabriel M. Veith, Andrew R. Lupini, Sergey Rashkeev, Stephen J. Pennycook, David R. Mullins, Viviane Schwartz, Craig a. Bridges and Nancy J. Dudney, - In-press - Journal of Catalysis (2008).
  • “Nanoparticles of Gold on y-
  • Al2O3 Produced by dc Magnetron Sputtering”, G. M. Veith, A. R. Lupini, S. J. Pennycook, G. W. Ownby, N. J. Dudney, J. Catalysis, 231(1), 151-158 (2005).

Polymer-Based Multi-Component Materials. This research program is designed to realize a fundamental understanding of chemical and physical processes that will enable the design and control of interfaces, dispersion, and ordering in multi-component polymer systems. These lightweight and versatile mixtures are key components in the next generation of advanced materials, impacting a broad range of current and future DOE technology needs, including organic photovoltaics, energy storage media, fuel cell membranes, and stronger light-weight materials that result in energy savings. To achieve the goals of this project, tailored synthesis of various types of materials is carried out. These include 1) anionic synthesis of polymers, including complex architecture block copolymers, 2) synthesis of novel crosslinked polymer nanoparticles of controlled size, shape, softness, and chemical composition, and 3) synthesis of polymer grafted carbon nanotubes using novel strategies for growing tailored polymer chains from desired locations and at desired densities. The study of these well defined nanostructured materials provides the basis for achieving the central goal of this research program, which is to develop a fundamental understanding that can be utilized to control and optimize interfaces in multi-component polymer-based systems and correlate these molecular level interactions to the dispersion, morphology, and properties of these promising materials. Contact:  Jimmy Mays.

Various miktoarm (mixed arm) star and multigraft architectures.

Selected References:

  • “Enhanced Polymer Grafting from Multi-Walled Carbon Nanotubes through Living Anionic Surface Initiated Polymerization”, G. Sakellariou, H. Ji, J. W. Mays, and D. Baskaran, Chem. Mater., 20, 6217 – 6230 (2008).
  • “Macromolecular Architectures by Living and Controlled/Living Polymerizations”, N. Hadjichristidis, H. Iatrou, M. Pitsikalis, and J. W. Mays, Prog. Polym. Sci., 31, 1068-1132 (2006).

Alloy Design with Well-Controlled Microstructures.  One of the fundamental goals in materials science is to understand the relationship between materials properties and microstructures. Attaining detailed knowledge of this relationship requires simple systems with well controlled microstructures, allowing for precise investigation and modeling of multi-scale properties.  However, many materials of interest have high melting points or are highly reactive, making traditional processing difficult. The Alloying Behavior and Design group has facilities for containerless synthesis of these materials in a high temperature optical floating zone furnace Many single crystals and multi-phase alloys with controlled microstructure have been successfully produced by directional solidification in this furnace. Examples include well-aligned, dislocation-free single crystal molybdenum micropillars with sizes ranging from 300 to 1500 nm. Those pillars were produced by etching away the matrix in a directionally solidified NiAl-Mo pseudo-binary eutectic alloy. The pillar size can be controlled by changing the solidification speed. It is found that their mechanical properties are strongly size dependent. These micropillars provide a unique way to study the fundamentals of small-scale mechanical behavior.  Contact: Easo George.


High temperature optical floating zone furnace.

    SEM micrograph showing a well-ordered array of ~550-nm Mo alloy pillars produced by directional solidification.

Selected References:

  • H. Bei, E. P. George, E. A. Kenik, and G. M. Pharr, “Directional solidification and Microstructures of Cr3Si Alloys”, Acta Mater., 51 (2003): 6241-6252.
  • H. Bei, and E. P. George, “Microstructures and mechanical properties of a directionally solidified NiAl-Mo eutectic alloy,” Acta Mater, 53 69-77 (2005).
  • H. Bei, Y. F. Gao, S. Shim, E. P. George, and G. M. Pharr, “Strength differences arising from homogeneous versus heterogeneous dislocation nucleation,” Phys Rev B, 77 (2008): 060103.
  • H. Bei, S. Shim, G. M. Pharr, and E. P. George, “Effects of pre-strain on the compressive stress-strain response of Mo-alloy single-crystal micropillars,” Acta Mater, 56 (2008): 4762.

Nanomaterials Chemistry. This program conducts research related to the synthesis and characterization of nanoscopic materials as well as ionic liquids for fundamental investigation of separation and catalysis processes. This group also conducts the applied research related to the applications of nanomaterials in advanced scintillators for radiation sensing, catalysts for fuel cells, radioactive tracers for medical imaging, novel electrodes for energy storage, and sensing devices for biological agents. Extensive synthesis capabilities exist within the group for preparation of mesoporous materials (oxides and carbons), low-dimensional materials (e.g., quantum dots and nanowires), sol-gel materials, inorganic and hybrid monoliths (e.g., membranes), and nanocatalysts. Solvothermal, ionothermal, templating synthesis, chemical vapor deposition (CVD), and atomic layer deposition (ALD) methods are extensively utilized in the group for tailored synthesis of nanostructured materials. An array of techniques for characterizing physical and chemical properties related to separation and catalysis are in place or are currently being developed.  Contact: Sheng Dai.

The TEM image of ordered mesoporous carbon synthesized at ORNL via molecular self-assembly.

Selected References:

  • Liang, CD., Li, Z., Dai, S., Mesoporous Carbon Materials: Synthesis and Modification, Angew. Chem. International Edition, 47, 3696, (2008).
  • Jiang, D. E.; Tiago, M. L.; Luo, W. D.; Dai, S. "The "Staple" motif: A key to stability of thiolate-protected gold nanoclusters," J. Am. Chem. Soc., 130, 2777 (2008).
  • Shiju, N. R., Liang, X. H., Weimer, A. W., Liang, C., Dai, S., and Guliants, V. V., "The role of surface basal planes of layered mixed metal oxides in selective transformation of lower alkanes: Propane ammoxidation over surface ab planes of Mo-V-Te-Nb-O M1 phase", J. Am. Chem. Soc. 130, 5850 (2008).
  • Wang, X. Q., Liang, C. D., and Dai, S., "Facile synthesis of ordered mesoporous carbons with high thermal stability by self-assembly of resorcinol-formaldehyde and block copolymers under highly acidic conditions", Langmuir 24, 7500 (2008).
  • Wang, X. Q., Jiang, D. E., and Dai, S., "Surface modification of ordered mesoporous carbons via 1,3-dipolar cycloaddition of azomethine ylides", Chem. Mat. 20, 4800 (2008).
  • Steinhart, M., Liang, C. D., Lynn, G. W., Gosele, U., and Dai, S., "Direct synthesis of mesoporous carbon microwires and nanowires", Chem. Mat. 19, 2383 (2007).
  • Liang, C.; Dai, S. “Synthesis of Mesoporous Carbon Materials via Enhanced Hydrogen-Bonding Interaction,” J. Am. Chem. Soc.; 128, 5316 (2006).
  • Jiang, D.E.; Sumpter, B. G.; Dai, S. “Structure and Bonding between an Aryl Group and Metal Surfaces,” J. Am. Chem. Soc.,128, 6030-6031(2006).
  • Jiang, D. E.; Sumpter, B. G.; Dai, S. "Olefin adsorption on silica-supported silver salts - A DFT study," Langmuir, 22, 5716-5722 (2006).
  • Yan, W. F.; Brown, S.; Pan, Z. W.; Mahurin, S. M.; Overbury, S. H.; Dai, S. “Ultrastable Gold Nanocatalyst Supported by Nanosized Non-Oxide Substrate,” Angew. Chem. Int. Ed. 45, 3614-3618 (2006).
  • Chen, B. L.; Liang, C. D.; Yang, J.; Contreras, D. S.; Clancy, Y. L.; Lobkovsky, E. B.; Yaghi, O. M.; Dai, S. "A microporous metal-organic framework for gas chromatographic separation of alkanes" Angew. Chem.-Int. Edit., 45, 1390 1393 (2006).

(a) Atomic-resolution cross-sectional transmission electron micrograph of a perovskite superlattice (repeated deposition of 2 unit cells each of SrTiO3, CaTiO3, and BaTiO3), (b) Surface x-ray diffraction intensity map recorded during homoepitaxial SrTiO3 growth, (c) and (d): PLD process and apparatus.

Epitaxial Films and Multilayers. This program focuses on the controlled growth of epitaxial oxide heterostructures and diamond films. Thin films and superlattices of metal-oxides (perovskites in particular) provide an ideal platform for the study of interfacial and confinement effects on the properties of complex and correlated materials. Pulsed laser deposition (PLD, ref.1) is used to grow epitaxial films of ferroelectrics, magnetic and multiferroic perovskites, high-temperature superconductors, and electro-optic materials. Superlattices with atomically abrupt interfaces (ref. 2) are achieved thanks to detailed in-situ investigations of the growth process, by using reflection high-energy electron diffraction during growth, and detailed, ms-scale time-resolved surface x-ray diffraction studies performed at the Advanced Photon Source. Diamond films are produced via chemical vapor deposition (CVD) and energetic beam growth. Contact: Hans Christen.


  • H.M. Christen and G. Eres. “Recent advances in pulsed-laser deposition of complex oxides,” J. Phys.: Condens. Matter 20 264005 (2008).
  • H.N. Lee, H.M. Christen, M.F. Chisholm, C.M. Rouleau, and D.H. Lowndes. “Strong Polarization Enhancement in Asymmetric Three-Component Ferroelectric Superlattices,” Nature 433, 395 (2005).

(a) Vertical furnace for reel-to-reel reaction-conversion of high-temperature superconducting coatings on long metal tapes.
  (b) Cross-section TEM of self-assembled nanocolumn stacks of second-phase BaZrO3 in high-temperature superconducting films made by pulsed laser deposition.

Superconductive and Energy Efficient Materials.   The materials synthesis component of this program involves deposition of films and coatings for the attainment of novel or improved electronic properties.  A large portion of the work focuses on basic materials aspects of optimized, epitaxial oxide buffer layers and coatings of the high-temperature superconductors on metallic tape substrates.  Through Cooperative Research and Development Agreements, much of this research underpins the pre-commercial “2nd Generation” wire development at three U.S. companies, and includes capability to deposit reel-to-reel on lengths of substrate tape.  Other projects include epitaxial diamond and photovoltaic films on metallic substrate, and various approaches to controlling nanostructure through second-phase self-assembly in composite films.  Contact: David Christen.

Thermally-grown Cr-nitride on PEM fuel cell metallic bipolar plate. (Collaboration with DANA Corporation, Tennessee Technological University and the University of South Carolina)

Controlled Oxidation Processing of Metals as a Synthesis Approach. Oxidation (nitridation, carburization, etc.) reactions of metals are one of the most rapid, inexpensive, and technologically relevant methods of self constructing near-surface ceramic structures. They can result in the formation of a myriad of ceramic phase arrangements, ranging from nanoscale clusters and dispersions to external layers, varying from nanometers to tens and hundreds of microns thick.  A major advantage is that natural structures such as these typically exhibit long-term stability because their formation is driven by thermochemical energy minimization associated with phase stability in the presence of reactive species.  Internal and/or selective gas reactions can be used to precipitate new phases, modify existing phases, or preferentially segregate one or more elements from the substrate alloy metal to the surface.  Recent efforts have included: 1) thermal growth of electrically-conductive and corrosion-resistant Cr-nitride surfaces for proton exchange membrane (PEM) fuel cell bipolar plates, 2) the use of intermetallic precursors as a template to form complex ceramic phase structures, including anti-perovskite nitrides such as Cr3PtN and Fe3PtN, and ternary carbide phases such as Co6Mo6C2, and 3) simple and complex nanoscale dispersions by internal oxidation reactions.  Contact: Michael Brady.

Select References:

  • M.P. Brady, B.Yang, H. Wang, J.A. Turner, K.L. More, M. Wilson, and F. Garzon, “Formation of Protective Nitride Surfaces for PEM Fuel Cell Metallic Bipolar Plates,” JOM-Journal of Metals, Minerals, and Materials Society, 58 (8), pp. 50-57 (August 2006).
  • M.P. Brady, P.F. Tortorelli, K.L. More, E.A Payzant, B.L. Armstrong, H.T. Lin, M.J. Lance, F. Huang, and M.L Weaver, “Coating and Surface Modification Design Strategies for Protective and Functional Surfaces,” Materials and Corrosion, 56, No. 11, pp. 748-755 (2005).
  • M.P. Brady and P.F. Tortorelli, “Alloy Design of Intermetallics for Protective Scale Formation and for Use as Precursors for Complex Ceramic Phase Surfaces,” Intermetallics, 12 (7-9): 779 (2004).

Chemical Vapor Deposition of Protective and Structural Coatings. The focus of this program is the deposition of a wide variety of elemental metals, carbides, oxides, and nitrides as coatings.  Complex systems with both multicomponent phases, and multiphase systems have been controllably prepared.  Recent efforts have been on the deposition of light metals such as aluminum and magnesium, with the chemical vapor deposition of magnesium demonstrated for the first time at ORNL.  In addition, fluidized bed coating of particulates has been perfected, with substantial work in the area of multilayer coatings on nuclear fuel particles.  Chemical vapor infiltration capability and experience are extensive, with ceramic and carbon fiber form infiltrated with carbon, silicon carbide, boron carbide, titanium boride, and other refractory materials.  Contact: Ted Besmann.


A highly controlled, plasma activated CVD system that has been used for multi-element film deposition.


Schematic of the fluidized bed coating of particulate substrates.


Selected References:

  • L. Tan, T. R. Allen, J.D. Hunn, J.H. Miller, ”EBSD for microstructure and property characterization of the SiC-Coating in TRISO fuel particles,” Journal of Nuclear Materials, Vol. 372, pp. 400-404 (2008).
  • V.G. Varanasi, T.M. Besmann, E.A. Payzant, T.L. Starr, T.J. Anderson, “Thermodynamic Analysis and Growth of ZrO2 by Chloride Chemical Vapor Deposition,” Thin Solid Films, 516 (18)  pp 6133-6139 (2008).
  • T. M. Besmann, J. J. Henry, E. Lara-Curzio, J. W. Klett, D. Haack, K. Butcher, “Optimization of a carbon composite bipolar plate for PEM fuel cells,” Solid State Ionics, Materials Research Society Symposium Proceedings Vol. 756 415-422 (2003).
  • T. M. Besmann, J. C. McLaughlin, K. J. Probst, T. J. Anderson, and T. L. Starr, “Development of a Scaled-Up CVI System for Tubular Geometries, pp. 560-7," Proc. 14th Intl. Conf. on Chemical Vapor Deposition/EuroCVD 11, eds. M. D. Allendorf and C. Bernard, Electrochemical Society, Pennington, NJ (1997).

Combustion Synthesis.  Combustion synthesis (glycine–nitrate type) is a process utilized by our research staff in the Surface, Processing and Mechanics group to produce nanocrystalline powders due to this method’s ability to rapidly produce large quantities of powders with a high degree of homogeneity and precise compositional control.  In this process, a mixture of aqueous solution precursors and a fuel is heated to its auto-ignition temperature to produce a fine nanopowder.  The benefits of this technique include the ability to produce single phase materials in a single step with precise compositional control.  Due to its flexibility in composition tailoring, complex chemistries are easily achievable.  Multiphase mixtures can also be synthesized, i.e., Ni/YSZ.  A wide variety of materials have been synthesized at ORNL using this technique.  Contact: Beth Armstrong.


Selected metal nitrate solutions are mixed with a fuel, dehydrated, and heated until auto ignition.
  Real-time image of synthesis captured during combustion. Ash seen above and around flame is the desired product. Combustion exaggerated for sake of image.

Selected References:

  • B. Armstrong, Materials And Manufacturing Processes, 11 [6] 999 (1996).
  • B. Armstrong, "Consolidation and Processing of Nanocyrstalline Zirconia," M.S. Thesis, University of California, Los-Angeles (2000).



Materials Chemistry.  One of the goal of this program is to discover and exploit controlled synthetic methods to produce, characterize and ultimately control novel inorganic nanometer-scale materials and to gain a fundamental understanding of how the spatial or temporal confinement of atomic or molecular species onto or within materials impact the physicochemical properties.  How we control the nucleation and growth of inorganic nanoparticles, solution based thin films, highly ordered nanotube arrays through electrochemical anodization, and self-assembly assisted synthesis of mesoporous nanostructures are major research themes.  To address these issues, we will use a combination of synthesis, neutron scattering and advanced modeling to aid discovery and development of a quantitative, molecular level description of molecule-molecule and molecule-surface interactions by collecting detailed information regarding structure, dynamics and chemical activity.  Our work in inorganic thin film is focused on epitaxial growth of oxides from physical vapor deposition and chemical solution deposition techniques.  Classes of materials under study include unconventional superconductors, high temperature superconductors and electro-optic perovskites.  Methods of characterization include x-ray diffraction, small angle x-ray and neutron scattering, atomic force microscopy, scanning electron microscopy, x-ray photoelectron spectroscopy, electronic transport property measurements, and transmission electron microscopy.  Our work in nanoparticles is focused on oxide and nitride materials with interesting optical, magnetic, or catalytic properties, and metallic particles for electronic and catalytic applications.  Finally, this group is also involved in assisting US industries in the development and commercialization of high performance superconductor wires and photovoltaic devices.  Contact: M. Parans Paranthaman.

SEM images of electrochemical grown HfO2 nanotube arrays (left) and the corresponding substrate after nanotube removal (right).  The right image shows the self-assembled hexagonally shaped HfO2 dimples.

Selected References:

  • “Aligned ZnO Nanorod Arrays Grown Directly on Zinc Foils and Zinc Spheres by a Low-Temperature Oxidization Method,” Zhanjun Gu, M. Parans Paranthaman, Jun Xu, and Zheng Wei Pan, ACS Nano, DOI: 10.1021/nn800759y, January 13, 2009.
  • “Zinc Oxide Microtowers by Vapor Phase Homoepitaxial Regrowth,” Zhengwei Pan, John D. Budai, Zu Rong Dai, Wenjun Liu, M. Parans Paranthaman, and Sheng Dai, Advanced Materials, 21, 1-7 (2009).
  • “Enhanced flux pinning and critical currents in YBa2Cu3O7-Õ films by nanoparticle surface decoration: Extension to coated conductor templates,” T. Aytug, M. Paranthaman, K. J. Leonard, K. Kim, A. O. Ijaduola, E. Tuncer, J. R. Thompson, and D. K. Christen, J. Appl. Phys. 104, 043906 (2008).
  • “MOD buffer/YBCO approach to  fabricate low-cost second generation HTS wires,” M. P. Paranthaman, S. Sathyamurthy, M. S. Bhuiyan, P. M. Martin, T. Aytug, K. Kim, M. Fayek, K. J. Leonard, J. Li, A. Goyal, T. Kodenkandath, X. Li, W. Zhang, and M. W. Rupich, IEEE Trans. On Appl. Supercond., 17 (2), 3332-3335, June 2007.
  • “High-performance high-Tc superconducting wires,” S. Kang, A. Goyal, J. Li, A. A. Gapud, P.M. Martin, L. Heatherly, J. R. Thompson, D. K. Christen, F. A. List, M. Paranthaman, and D. F. Lee, Science 311 (5769): 1911-1914, March 2006.
  • “Effect of relative humidity on the crystallization of sol-gel lanthanum zirconium oxide films,” S. Sathyamurthy, K. Kim, T. Aytug, and M. Paranthaman, Chemistry of Materials, 18 (25), 5829-5831, Dec. 2006.

Low-dimensional Complex Oxides. Two of the most widely studied areas of condensed matter physics are complex materials and nanoscale behaviors.  Surprisingly, there has been very little crossover between these two fields as most of the nanophysics research being conducted uses “simple” materials such as metals or semiconductors instead of complex materials such as transition metal oxides or cuprates.  Due to the strong electronic correlation in many complex materials, it is exactly these systems that are the most likely to lead to observations of striking new phenomena under spatial confinement. To study the emergent phenomenon of complex oxides under spatial confinement, it is critical fabricate these materials at nanometer scale with correct stoichiometry. A combination of laser molecular beam epitaxy and state-of-the-art nanofabrication methods has been employed to achieve such a goal. In addition, the surface properties of the oxides have also been characterized at atomic scale since the presence of the surfaces is becoming increasingly important at nanometer scale. Contact: Jian Shen.


Epitaxial manganites thin films. Morphology (up) and spectroscopy (down) images.

  Fabricated manganite wire for transport measurements.

Selected References:

  • K. Fuchigami, Z. Gai, T. Z. Ward, L. F. Yin, P.C. Snijders, E. W. Plummer, and J. Shen, “Tunable Metallicity at La5/8Ca3/8MnO3 Surface by Oxygen Overlayer,” Phys. Rev. Lett. (to appear in Feb.).
  • T.Z. Ward, X.G. Zhang, L.F. Yin, X.Q. Zhang, Ming Liu, P.C. Snijders, S. Jesse, E.W. Plummer, Z.H. Cheng, E. Dagotto, J. Shen, “Time Resolved Electronic Phase Transitions in Manganites,” Phys. Rev. Lett. (to appear in March).
  • T.Z. Ward, S.H. Liang, K. Fuchigami, L.F. Yin, E. Dagotto, E.W. Plummer, and J. Shen, “Reemergent Metal-Insulator Transitions in Manganites Exposed with Spatial Confinement,” Phys. Rev. Lett. 100, 247204 (2008).
  • Hong-Ying Zhai, J.X. Ma, D.T. Gillaspie, X.G. Zhang, E.W. Plummer, and J. Shen, “Giant Discrete Steps in Metal-Insulator Transition in Perovskite Manganite Wires,” Phys. Rev. Lett. 97, 167201 (2006).



Catalytic Nanomaterials. This program focuses on the fundamental understanding of the catalytic behavior of nanomaterials through designed interfaces, controlled morphologies and particle sizes, and tailored functionalities. The materials of interest include high surface area porous materials, alloy nanoparticles, carbon catalysts, carbides, and hydrothermally grown crystals. We have extensive synthesis expertise on four directions: (1) template-assisted synthesis of mesoporous materials including soft-template and hard-template synthesis of ordered mesoporous carbons and oxides; (2) metal and metal oxide nanoparticles through surfactant-mediated, solvothermal, and template-assisted synthesis methods; (3) nanocatalysts supported on porous materials by co-synthesis and incipient wetting synthesis; and (4) chemical modification of catalyst supports via surface reactions. Contact: Chengdu Liang.




Growth Mechanisms and Controlled Synthesis of Nanomaterials. This program focuses on understanding and controlling the growth mechanisms of nanomaterials through non-equilibrium synthesis methods and the development and application of time-resolved, in situ and real-time diagnostic techniques. The growth mechanisms of a variety of nanoparticles, nanowires and carbon nanomaterials by laser vaporization and chemical vapor deposition are explored using integrated time-resolved optical spectroscopy and fast ICCD-imaging in special windowed growth environments. Nanomaterial growth by catalyst assisted processes (e.g. single-wall carbon nanotubes, SWNTs) and catalyst-free processes (e.g. single-wall carbon nanohorns (SWNHs), graphene, oxide nanorods) are compared and understood with integrated theory and predictive modeling. The program produces small quantities of well-characterized nanomaterials with tunable sizes, shapes, and morphologies. Multi-gram quantities of selected nanomaterials are produced by high-power laser vaporization in the ALPS (Advanced Laser Processing and Synthesis) laboratory, where processes for laser-CVD and rapid laser annealing of nanomaterials are also developed. Novel techniques are also explored to understand and control the chemical vapor deposition of aligned nanomaterials such as long, vertically-aligned single- and multi-walled carbon nanotube arrays (VANTAs). . The in situ diagnostic-controlled synthesis and processing approach in the program is used to explore new materials and mechanisms for doped, decorated, and filled nanomaterial hybrids predicted to distribute charge for energy-related functionality. These well-characterized materials undergo further processing in various programs throughout the laboratory to explore energy related applications such as activated and decorated SWNH for hydrogen storage, purified SWNT as electrodes for hybrid organic/inorganic photovoltaics and solid state lighting, and VANTAs for thermal management. Contact: David Geohegan

Nanomaterial growth by laser vaporization (SWNTs and SWNHs), chemical vapor deposition (VANTAs and SnO2 nanowires), or condensed phase conversion (oxide nanorods) are studied by in situ, real-time diagnostics (e.g. ICCD imaging of PLD plume thermalization in background gases).

Selected References:

  • A. A. Puretzky, G. Eres, C.M. Rouleau, I. N. Ivanov, and D. B. Geohegan "Real-time imaging of vertically aligned carbon nanotube array growth kinetics." Nanotechnology 19(5) 055605 (2008).
  • D. B. Geohegan, A. A. Puretzky, D. Styers-Barnett, H. Hu, B. Zhao, H. Cui, C. M. Rouleau, G. Eres, J. J. Jackson, R. F. Wood, S. Pannala, J. Wells “In situ time-resolved measurements of carbon nanotube and nanohorn growth”, Physica Status Solidi B 244 (11), 3944 (2007).
  • Z. Liu, D. J. Styers-Barnett, A. A. Puretzky, C. M. Rouleau, D. Yuan, I. N. Ivanov, K. Xiao, J. Liu, and D. B. Geohegan, “Pulsed Laser CVD Investigations for Single-Wall Carbon Nanotube Growth Dynamics”, Appl. Phys. A 93(4), 987-993 (2008).

Organic Nanowires. This program focuses on the synthesis and characterization of single-crystalline organic nanostructures which promise superior optical and charge transport properties compared to organic thin films. Organic nanowires that self-assemble from small-molecule semiconductors and conducting polymers have attracted enormous interest for use in organic electronics (e.g. memory and integrated logic) and energy-related devices (e.g. photovoltaics and OLEDs). Through a fundamental understanding of the behavior of these low-dimensional organic semiconducting building blocks, this program seeks to address and isolate nanoscale science that govern the macroscale functionality of energy related devices. For example, the design of organic solar cells requires control not only of the electronic properties of light-absorbing donor and acceptor components, but also of phase-separated nanoscale morphologies. Synthesized single nanostructures are tested through the use of lithographically-patterned electrodes, and nanowire assemblies are integrated into organic electronic test structures using multi-glove-box inert processing and testing environments at the Center for Nanophase Materials Sciences. Contact: Kai Xiao

SEM, TEM, and SAED electron micrographs of single-crystal organic nanowires of Ag-TCNQ   Plastic memory devices based on Cu-TCNQ organic nanowires

Selected References:

  • K. Xiao, J. Tao, A. A. Puretzky, I. N. Ivanov, S. T. Retterer, S. J. Pennycook, D. B. Geohegan, “Selective patterned growth of single-crystal Ag-TCNQ nanowires for devices by vapor-solid chemical reaction”, Adv. Funct. Mater. 18, 3043 (2008).
  • K. Xiao, J. Tao, Z. Pan, A. A. Puretzky, I. N. Ivanov, S. J. Pennycook, D. B. Geohegan, “Single-crystal organic nanowires of copper-tetracyanoquinodimethane: synthesis, patterning, characterization, and device application”, Angew. Chem. Int. Ed. 46, 2650 (2007).
  • Z. Zhou, K. Xiao, R. Jin, D. Mandrus, J. Tao, D. B. Geohegan, S. J. Pennycook, “One-dimensional electron transport in Cu-tetracyanoquinodimethane organic nanowires”, Appl. Phys. Lett. 90, 193115 (2007).
  • K. Xiao, I. N. Ivanov, A. A. Puretzky, Z. Liu, D. B. Geohegan, “Directed integration of tetracyanoquinodimethane-Cu organic nanowires into prefabricated device architecture”, Adv. Mater. 18, 2184 (2006).

Multiple Forms of Carbon Materials. The materials synthesis and development activity in Carbon Materials Technology Group at ORNL is focused on advanced carbon materials, in support of energy-related programs of the U.S. government. The Group has developed a unique monolithic molecular sieve (CFCMS) for use in gas separations, air purification, organic removal from waste water streams, and gas storage. By varying the nature of carbon fibers and the activation method, the separation selectivity of molecular sieves can be tailored to specific applications, such as capture of CO2 from air, separation of H2S from natural gas, removal of toxic gases and vapors, and for adsorptive methane storage. Metal-promoted nanoporous carbon structures are being studied for their enhanced adsorptive storage capacity for hydrogen at near ambient temperatures. A new research direction is fabrication of low-cost carbon fibers derived from renewable sources, such as lignin, a major component of wood. The Group’s unique synthesis and manufacturing facilities include laboratory pilot units for melt-spinning, carbonization and activation of fibers, and for manufacturing of carbon fiber monoliths with desired shape and morphology. In addition, the Group has developed innovative processes for synthesis of carbon and graphite foams used as thermal management substrates; of carbon/carbon composites and carbon-bonded carbon fibers used as thermal shields for space and nuclear applications; and for in-situ growth of multiwalled carbon nanotubes used as reinforcing additives for composite materials. Recently group members were involved in development of an improved method for carbon coating of nuclear fuel microspheres for the next generation of nuclear plants and in the graphite technology development program. Contact: Timothy Burchell

Carbon Foams
Carbon fibers molecular sieve (CFCMS)

Selected References:

  • X. Wu, N. C. Gallego, C. I. Contescu, H. Tekinalp, V. Bhat, F. S. Baker, M. C. Thies, D. D. Edie: “The effect of processing conditions on microstructure of Pd-containing activated carbon fibers”, CARBON  46 (2008) 54-61.
  • Pappano PJ, “A novel approach to fabricating fuel compacts for the Next Generation Nuclear Plant (NGNP),” Journal of Nuclear Materials, 381 (2008) 25-38.
  • Burchell T.D., Omatete O.O., Gallego N.C., Baker F.S., “Use of Carbon Fiber Composite Molecular Sieves for Air Separation,” Adsorption Science & Technology, 23 (2005) 175-194.
  • Klett J.W., McMillan A.D., Gallego N.C., Burchell T.D., Walls C.A., “Effects of Heat Treatment Conditions on the Thermal Properties of Mesophase Pitch-Derived Graphitic Foams,” CARBON, 42 (2004) 1849-1852.
  • Gallego N.C. and Klett J.W., “Carbon Foams for Thermal Management,” CARBON, 41 (2003) 1461-1466.
  • Burchell, T. D., Judkins, R. R., Rogers, M. R., and Williams, A. M., “A Novel Process for the Separation of Carbon Dioxide and Hydrogen Sulfide from Gas Mixtures”, CARBON, 35 (1997) 1279-1294.




 Oak Ridge National Laboratory