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MSD - Materials Sciences Division

Condensed Matter and Materials Physics

Core Research Areas: Experimental Condensed Matter Physics, Theoretical Condensed Matter Physics, Physical Behavior of Materials, and Mechanical Behavior of Materials and Radiation Effects.

This program area focuses on fundamental understanding and control of materials and on discovery of new phenomena through activities in experimental and theoretical condensed matter and materials physics. This is accomplished through studies of structural, mechanical, electrical, magnetic and optical properties of materials. Research that characterizes the response of materials to temperature, stress, electric and magnetic fields, radiation, chemical and electrochemical environment, proximity to surfaces or interfaces, and to the existence and motion of intrinsic and extrinsic defects is conducted. 

The program area includes the development of predictive models for discovery of new materials with targeted properties, new materials properties and interpretation of experiment.  It emphasizes co-operative and correlation effects which can lead to formation of new quasi-particles, new phases of matter and unexpected phenomena.

Programs

Characterization of Functional Nanomachines

Program Leader: Michael Crommie
Co-PI's: Carlos Bustamante, Marvin Cohen, Jean Frechet, Steven Louie, Alex Zettl

This project establishes a multidisciplinary team at LBNL to develop, characterize, and better understand the fundamental behavior of mechanical structures at the nanoscale. Two paths will be followed toward this goal: (1) naturally occurring bio-motors will be harnessed to take advantage of the molecular mechanisms provided by Nature, and (2) new synthetic molecular machines will be designed in a molecule-by-molecule fashion. The first direction involves exploring chemically engineered molecular structures, purposefully designed with specific mechanical functions in mind. The second involves exploitation of the unique mechanical properties of graphene and nanotube-based nanostructures to create novel, nanomechanical devices. A common theme is to explore the fundamental mechanical response of nanostructures to external forces (such as pressure or electromagnetic stimulus) and internal changes (such as phase transitions and chemical reactions) and to clarify the basic mechanisms by which they convert energy from one form to another. These efforts will help form the scientific foundation underlying new molecular-mechanical nanotechnology with applications in areas of importance to DOE including chemical and photo-sensing, computation, power generation, and active surface control.

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Electronic Materials

Program Leader: Ali Javey
Co-PI's: Joel Ager, Daryl Chrzan, Oscar Dubon, Zuzanna Liliental-Weber, Wladyslaw Walukiewicz, Junqiao Wu, Kin Man Yu

The goal of the Electronic Materials Program is to advance and expand the fundamental understanding of the materials science of semiconductors. The research focuses on the relationships between synthesis and processing conditions and the structure, properties, and stability of semiconductor materials systems. Progress in these areas is essential for the performance and reliability of a number of technologies that lie at the heart of the DOE mission, including solar power conversion devices, solid state sources of visible light, visual displays, and a large variety of sensors and power control systems for energy generation, conservation, distribution and use.

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Mechanical Behavior of Advanced Materials

Program Leader: Robert Ritchie
Co-PI: Tony Tomsia

This program is focused on the development of an understanding of the mechanical behavior of next generation structural materials, in particular involving mechanical properties that are influenced by factors operating at a wide range of length-scales. Our goal is to design, synthesize, and characterize (structurally and mechanically) a new series of hybrid structural materials, whose unique properties derive from hierarchical architectures controlled over length-scales from nano to macro dimensions. The inspiration for these structures is biological; our goal is to defeat the law of mixtures (as in Nature) by devising complex hierarchical structures comprising weak constituents into strong and tough (non-biological) hybrid (polymer-ceramic & metal-ceramic) materials, which display far superior properties to their individual constituents. The research approach combines mechanistic understanding of structural behavior at multiple length-scales, the ability to synthesize such materials using novel techniques, the control of structural features (particularly interfaces) at the nanoscale, the ability to mechanically characterize such structures at atomic, molecular, nano, micro to macroscopic dimensions, and the evaluation of the suitability of these (non-biological) structures/systems for technological application.

Our current objective is the design, fabrication and theoretical modeling of new hybrid structural (non-biological) composites, and their mechanical property evaluation, with a sharp focus on developing high specific strength and toughness with lightweight materials. We are making an integrated and iterative effort toward comprehending, modeling and processing of several ceramic/metal, polymer/metal and ceramic/polymer hybrid systems, with the following principal thrusts:

Design and fabrication of new hybrid materials based on the notion of hierarchical structure, combined with innovative processing (initially using the concepts of "ice templating"), to make (in practical dimensions) such new hybrid (hierarchical) structural materials

Structural characterization and quantitative mechanical evaluation of damage-tolerant properties at all length-scales from near-nanoscale to macroscopic dimensions

Phenomenological and theoretical modeling of the microstructural evolution and the salient strength/toughening mechanisms at differing length-scales.

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Nanoscale Magnetic Materials

Program Leader: Peter Fischer
Co-PI's: Charles Fadley, Frances Hellman, Jeffrey Kortright, Patrick Naulleau

In this program, novel magnetic materials and nanoscale structures are synthesized and studied with a powerful range of techniques. The systems include vapor-phase deposited thin films and multilayers, patterned nanoscale systems, epitaxial and amorphous materials, metastable alloys, complex oxides, and ferroelectric/multiferroic films that are relevant to spintronics and magnetics. Calorimetry yields electron, phonon, and magnon densities of states, as well as magnetic ordering temperatures. Advanced synchrotron-radiation techniques yield element-specific electronic and magnetic structures, with spatial resolutions from micron to sub-nanometer scale, as well as time resolution to the picosecond scale. The methods include resonant soft x-ray scattering, soft x-ray microscopy, and high resolution spectroscopies (core- and valence photoelectron, x-ray absorption, x-ray emission and inelastic scattering), in some cases excited by standing waves.

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Nanostructured Materials for Thermoelectric Energy Conversion

Program Leader: Rachel Segalman
Co-PI's: Joel Moore, R. Ramesh, Peidong Yang, Jeffrey Urban

Thermoelectric energy conversion or refrigeration is attractive due to the very high reliability, long cycle life, and lack of moving parts. In spite of these advantages, many thermoelectrics are daunted by low efficiency, high cost, and lack of scalability. In response, this program is scoped to investigate how nanostructuring can improve thermoelectric performance for materials that have the potential to be scalable, low cost, and efficient. The efficiency of such devices is quantified by a dimensionless figure of merit, ZT = S2σT/κ, where S is the thermopower or Seebeck coefficient, and σ and κ are the electrical and thermal conductivities of the material. Increasing ZT has historically been extremely difficult due to the coupling between these thermoelectric parameters. Our approach to this problem is to identify paradigms at which these parameters can become decoupled by unique transport phenomenon at the nanoscale and improve the performance.

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Novel sp2-Bonded Materials and Related Nanostructures

Program Leader: Alex Zettl
Co-PI's: Carolyn Bertozzi, Marvin Cohen, Michael Crommie, Alessandra Lanzara, Steven Louie

The sp2 program studies, both theoretically and experimentally, sp2-bonded structures which include carbon nanotubes, graphene, nanowires, onions, fullerenes, nanocrystals, hybrid structures, non-carbon nanomaterials (including BN), and nanococoons. We are interested in the design, synthesis, characterization, and application of sp2-bonded materials whose dimensions range from 1-100 nm. This program has three major thrusts:

1-Fundamentals: Focus is placed on theoretical predictions of new stable structures, theoretical and experimental examinations of intrinsic electronic, magnetic, and mechanical responses, transport measurements (electrical resistivity, thermal conductivity, isotope effects, Raman, photoemission spectroscopy, TEM, STM), and mechanical properties and tensile strength.

2-Functionalized nanosystems: where two or more distinct nanostructures are brought together and allowed to interact. Here we focus on methodologies to integrate nanosystems comprised of nanotubes and other nanoparticles interfaced with complementary nanostructures.

3-Directed growth of nanostructures: where novel synthesis methods are explored for non-equilibrium growth of sp2 -based and other nanoscale materials.

This program also seeks to develop specialized instrumentation for synthesis, characterization, and applications.

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Quantum Materials

Program Leader: Joe Orenstein
Co-PI's: Robert Birgeneau, Edith Bourret-Courchesne, Robert Dynes, Alessandra Lanzara, Dung-Hai Lee, Joseph Orenstein, Ashvin Vishwanath

Quantum physics provides the theoretical basis for our understanding of the electronic properties of all materials. However, there exists a fascinating sub-class of condensed matter systems, now widely known as quantum materials, in which quantum mechanics plays an especially profound role in determining the nature of macroscopic order parameters and the phase-transitions between them. In some cases, such as superconductors, this occurs because the order parameter is explicitly a quantum mechanical object. In many other such systems, quantum effects dominate the physics because of the interplay between competing order, frustration, strong interactions, and low-dimensionality. These systems display a marvelously rich and diverse range of physical phenomena. Transition metal oxides, e.g. manganites, cuprates, ruthenates and cobaltates, are systems whose interacting charge, spin, orbital, and lattice degrees of freedom exemplify the diversity of quantum materials.

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Spin Physics

Program Leader: Joe Orenstein

An important objective of semiconductor spintronics is to generate electron spin polarization, and to preserve it for a sufficiently long time for possible information processing. On one hand, spin-orbit coupling enables optical generation and manipulation of spin polarization. However, spin-orbit interactions can also lead to rapid loss of the spin lifetime.

Energy dissipation is the number one problem facing continued evolution of electronic information technology. Recently developed theories predict that the flow of spin can, in principle, proceed with less dissipation of energy than the flow of charge. Furthermore, new research has indicated that it is possible to control the flow of electron spin purely via electric field. In this project, we investigate the fundamental physics that underlies the potential for electric-field gated spin-based devices. We believe the information obtained through our research will play an essential role in enabling the development of this new technological paradigm.

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Sub-wavelength Metamaterial Physics and Applications

Program Leader: Yuegang Zhang
Co-PI's: Ron Shen, Feng Wang, Eli Yablonovitch

The spectacular on-going development of metamaterials provides an exciting gateway to realize unique and unprecedented optical properties and functionalities not existing in natural materials. These artificially-engineered composites consist of 'meta-atoms' or 'meta-molecules' that can be tailored in shape and size, where their lattice constant and inter-atomic interaction can be precisely tuned at a deep sub-wavelength scale. In the past decade, an impressive progress has been made in the field, covering a wide variety of exotic optical properties. One of the most exciting properties of metamaterials is their ability to image object beyond the diffraction limit. The quest for the perfect lens initiated and inspired the research in the field of metamaterials and has driven the field for many years. Being able to have in the far field a perfect image of an object is the dream in many physics and technology research. We have already demonstrated considerable steps toward this goal and believe that the physics and technological aspects to be revealed in this project will bring practical solution to real time sub-diffraction imaging in far field and will have revolutionary applications in fields ranging from optical communication to energy harvesting.

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Theory of Materials

Program Leader: Steven Louie
Co-PI's: Marvin Cohen, Dung-Hai Lee

This is a broad-based program to understand and compute material properties and behaviors involving three principal investigators and covering two complementary efforts: 1) quantum theory of materials, and 2) strongly correlated electron systems. Novel materials and new concepts are explored. A variety of theoretical techniques are employed, ranging from first-principles electronic structure calculations to new conceptual and computational frameworks suitable for complex materials/nanostructures and strongly interacting electron systems. One focus is to investigate realistic systems employing microscopic, first-principles approaches. Model systems are also examined. Studies include bulk materials, nanostructures, superconductors, surfaces and interfaces, and reduced-dimensional systems. Close collaboration with experimentalists is maintained. Another emphasis is to push the frontier of theory beyond the Landau paradigm toward a framework capable of describing and predicting the behavior of strongly correlated systems. Through interaction with experiment, new phases, new phase transitions, and new organization principles may be discovered. Equally important is the development of computational methods suitable for increasingly complex materials and strongly correlated materials.

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