Center for Nanophase Materials Sciences

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Center forNanophase Materials Sciences
A Proposed Nanoscale Science Research Center
atOak Ridge National Laboratory

• J. B. Roberto
• Associate Laboratory Director
• Oak Ridge National Laboratory

presentation to Basic Energy Sciences Advisory
Committee Gaithersburg, Maryland February 27, 2001
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Center for Nanophase Materials Sciences

• Outline
• Purpose and Philosophy
• Nanoscience andNeutron Scattering
• Scientific Thrusts
• Soft materials
• Complex nanophase materials systems
• Science-driven synthesis and simulation
• Operational Aspects

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Center for Nanophase Materials Sciences

• Purpose
• Advance nanoscale materials research through the
  integration of the unique neutron scattering
  capabilities of the SNS and the upgraded HFIR
  with nanomaterials synthesis and
  theory/modeling/simulation
• Provide the research infrastructure to ensure
  full utilization of SNS and the upgraded HFIR
  for nanoscale materials research
• Advance fundamental understanding of soft
  materials, complex nanophase materials, and
  collective phenomena that emerge on the
  nanoscale
• Provide a national and regional resource for
  nanoscale research in partnership with
  participating universities

A national resource for advancing the
understanding of nanoscale phenomena and
processes in materials
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Center for Nanophase Materials Sciences

• Philosophy
• Flexible
• Minimal permanent staff
• 10-12 research areas that continually evolve and
  change
• Responsive
• Significant university presence in staffing and
  governance
• Advisory Committee to guide equipment acquisition
  and scientific direction
• Highly leveraged and coordinated
• Infrastructure investments reflect national and
  regional needs
• Complements and extends existing laboratory and
  university research

A partnership that maximizes resources,
encourages interaction, and provides unique
facilities in support of cutting-edge nanoscale
research
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Nanoscience and Neutron Scattering
The intense neutron beams at SNS and HFIR will
make broad classes of nanoscale phenomena
accessible to structural and dynamical study

• Soft materialsincluding molecular interactions
  and nanostructures in polymers and folded
  proteins
• Interface scienceincluding nanomagnetism, thin
  molecular films and membranes, and
  organic/inorganic interfaces
• Nanophase materialsincluding nanostructured
  composites, ceramics, alloys, and materials with
  nanoscale spatial, charge, and magnetic ordering

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Neutron Scattering Upgrades at HFIR

• New and upgraded instruments
• Cold source intensity comparable to the worlds
  best
• Thermal neutron intensity increased 2-3 times
• Vigorous user program serving 500 users
  annually
• Complementary to SNS and other HFIR missions

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Spallation Neutron Source

• Worlds most advancedaccelerator-based
  pulsed-neutron source
• Neutron beams with more than 10 times the
  intensity of any existing pulsed neutron source
• 24 instrument stations
• Thermal and cold neutron moderators
• 1000-2000 users per year from universities,
  industry, and government laboratories
• Addresses a decades-long need for a new neutron
  source in the U.S.

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Complex Behavior in Nanophase Materials

• Richness of Physical Properties
• Self-organizing/assembling behavior of polymers,
  micelles, proteins
• ABO3 perovskite-structure complex metal oxides
  (CMOs)
• High-temperature superconductivity (HTS),
  ferromagnetism, ferroelectricity, colossal
  magnetoresistance (CMR), good electrical
  conductivity
• Only a subset of family of complex metal oxides
• Discovery Add a new component to a known
  material
• Well-known approach ? unexpected new phenomena
• Examples HTS and CMR (1 1 ? 2!)
• Complex systems are all around us
• Constitute most of the tangible universe are the
  basis for future technology
• Discovery requires exploring frontiers of
  complexity

Developing methods to synthesize and to
understand complex materials at the nanoscale has
the potential to provide significant societal
benefit
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Soft Materials Organic, Hybrid, and Interfacial
Nanophases

• Challenges
• Control of self-assembly and nanoscale structure
• Understanding morphology, symmetry, and phase
  behavior
• Neutron scattering opportunities
• SANS for large-scale structures
• Reflectometry for molecular-scale interfaces
• H/D contrast for atomic level details
• Science enabled
• Polymers and block copolymers in nanotechnology
• Novel nanostructures from block copolymers and
  biomolecule/nanotube assemblies
• Molecular interactions in solutions and at
  surfaces (nanofluidics)

Micellar network obtained from a dissolved
triblock copolymer
Model of cAMP-dependent protein kinase (Trewhella)
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Nanostructure in Condensed Phases

• Understanding 3-dimensional microphase separated
  states of block copolymers
• Dynamics of polymer-polymer diffusion
• Time resolved studies of morphological changes

Possible morphologies of Triblock Copolymers (F.S
. Bates, G.H Fredrickson, Physics Today, 52
(1999) 32)
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Molecular Orientation at Membranes
Melittin protein in a hybrid bilayer membrane
(NIST)
100
10-2
8
CD2
POSY-II
D2O
10-4
- melittin melittin
SURF
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Neutron Reflectivity
10-6
ADAM, NG-1
Melittin
MURR
Lipid Head Group
SNS
4
10-8
Cr
Au
? (Z) (1010 cm-2)
10-10
2
S
0
.
0
0
0
.
2
5
0
.
5
0
0
.
7
5
1
.
0
0
0
Si substrate
CH2
-2
0
20
40
80
100
120
140
60
Z(Å)
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Complex Nanophase Materials Systems

• Challenges
• Synthesis Choosing the right path in a
  bewildering array of materials
• Characterization Expanded energy, length, and
  time scales
• Neutron scattering opportunities
• Elastic and inelastic scattering
• High-resolution powder diffraction
• Science enabled
• Highly-correlated complex materials (stripes)
• Reduced dimensionality (materials with no bulk
  analogs)
• Magnetism and spin-dependent transport in
  magnetic nanostructures
• Functional nanophase materials

Striped ordering (Tranquada)
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Electronic Phase Separation in Transition Metal
Oxides
Clearly, highly correlated electron systems
present us with profound new problems that almost
certainly will represent deep and formidable
challenges well into this new century neutron
scattering is an absolutely indispensable tool
for studying the exotic magnetic and charge
ordering exhibited by these materials --R. J.
Birgeneau and M. A. Kastner, Science, 4/2000

• Highly correlated, complex materials
• Lattice, spin, and charge degrees of freedom
  tightly coupled
• Competing ground states

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Highly Correlated Systems Nanoscale Organization
of Charge and Spin
Snapshot of fluctuating quantum stripes--Zaanen
Static Paired Stripes --Mori, Chen, Cheong
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In-Situ Studies of Complex Nanophase Materials
Systems

• Clathrate systems
• Energy resource (natural gas clathrates)
• Carbon storage(CO2 clathrates)
• Isotopic tailoring
• Fuel cell electrolytes and membranes
• Carbon foams
• Structure-property correlation
• Nanophase composites
• Thermal barrier coatings
• Buried interfaces
• Battery materials

Clathrate hydrate structure type I
Neutrons characterize temperature and pressure
dependence of structures and physical properties
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Time-Resolved Nanoscale Phenomena Dictate
Properties of Complex Materials

• Non-equilibrium phase transformation kinetics
• needed for modeling properties
• guide synthesis and processing
• Amorphous-to-crystalline transitions
• nano- and micro-crystalline
• bulk amorphous alloys
• new approaches to nanophase materials
• Grain growth kinetics
• novel mechanical and physical properties
• Porous materials
• catalyst systems, surface science
• Reaction kinetics
• oxidation studies

Secondary phases microstructure depend on
cooling rate
Neutrons characterize nucleation growth of
secondary phases
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Science-Driven Synthesis and Simulation

• Simulation and virtual synthesis
• Terascale computing
• Multiple temporal and spatial scales
• Integration of molecular simulation and
  electronic structure
• Unique crystals for neutron scattering studies
• Thick film superlattices using high-speed pulsed
  laser deposition
• Nanostructured magnetic and spin systems
• Novel complex oxides
• Synthesis of complex nanoscale materials
• More efficient experimental search methods
  (combinatorial)
• More intelligent searching (simulation-driven
  synthesis)

Embed advanced synthesis in an environment of
state-of-the-art modeling/simulation and
characterization
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Synthesis and NanofabricationAn Unmet Need

• The Center will incorporate a significant
  synthesis effort in nanoscale materials related
  to soft matter, interfaces, and nanophase systems
• This will include polymers, macromolecular
  systems, exotic crystals, complex oxides, and
  other nanostructured materials and phases
• Nanofabrication facilities will provide a
  national resource for research materials related
  to the Centers focus areas
• SNS and HFIR will benefit from access to the most
  interesting research samples

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Synthesis of Complex Nanophase Materials Single
Crystals for Neutron Scattering
Ferromagnetic CMR oxide
P-wave superconductor
La0.7Sr0.3MnO3
Sr2RuO4
New Complex Materials New Nanoscale Phenomena
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Theory, Modeling, and Simulation

• Theory, modeling, and simulation (TMS) methods
  applicable to nanoscale systems made possible by
• Ever more powerful computers and corresponding
  advances in software and algorithms
• Merging of several computational techniques
  (e.g., quantum chemical and molecular dynamics)
  to provide high- fidelity simulations of
  nanoscale systems based on first principles theory

Self-assembly of nano-droplets
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Theory, Modeling, and Simulation (cont.)

• TMS is a key enabler for
• Narrowing the search for new materials
• Reducing the time needed to design and
  synthesize new materials
• Designing and optimizing new nanoscale
  technologies
• ORNL has leading expertisein terascale computing
  and applications to nanoscalematerials design
  and synthesis modeling

Fluid flow in a nanotube
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Operational Aspects

• Colocated with the SNS and ORNLs nanoscale
  materials programs
• Jointly operated with university partners
• Substantial support for student and faculty
  participation
• 50 of staff from other institutions (faculty,
  students, industrial and government laboratory
  researchers)
• Includes interdisciplinary Nanomaterials Theory
  Institute
• Includes facilities for synthesis of research
  materials and clean facilities for
  nanofabrication
• Incorporates specialized equipment for
  characterization

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Partnerships

• ORNL has strong partnerships with The University
  of Tennessee, Vanderbilt, and the State of
  Tennessee
• Distinguished Scientists Program and Science
  Alliance
• Collaborating and Distinguished Visiting
  Scientist appointments
• Undergrad/grad student researchers and
  postdoctoral scholars
• Joint Institute for Neutron Sciences (state
  funding)
• New UT-Battelle Management and Group of Core
  Universities
• Duke, Florida State, Georgia Tech, NC State,
  Virginia, Virginia Tech
• Other collaborators in the nanosciences include
  Harvard, Minnesota, Massachusetts, Pennsylvania,
  and Princeton
• Form interdisciplinary research teams with
  university scientists
• Offer a unique research experience to a new
  generation of graduate students and postdoctoral
  researchers

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Infrastructure

• A 100,000-sq. ft. building with laboratories,
  clean-room facilities, computer and office space
• Located next to SNS and visitor housing
• Access to ORNL materials characterization
  facilities and terascale computing center
• Equipment list prepared with input from 15
  universities
• Chemical and physical characterization
• Materials synthesis and nanofabrication
• Special sample environments for neutron
  experiments
• Computational infrastructure

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Center for Nanophase Materials Sciences at the SNS