Home > Press > UT, ORNL scientists gain new insights into atomic disordering of complex metal oxides
![]() |
Defect fluorite materials such as Ho2Zr2O7 have been previously characterized as having a disordered cubic structure when sampled over many unit cell repeats. However, (a) pair distribution functions obtained from neutron total scattering reveals that description is inaccurate at the sub-nanometer level. Instead, (b) the local structure can be accurately modeled with an orthorhombic, weberite-type configuration revealing a complex disordering mechanism in these oxides, operating over different length scales. CREDIT:ORNL |
Abstract:
A study led by the University of Tennessee and the Department of Energy's Oak Ridge National Laboratory could soon pay dividends in the development of materials with energy-related applications.
Three UT researchers--Maik Lang, assistant professor of nuclear engineering; Haidong Zhou, assistant professor of physics; and Jacob Shamblin, a graduate research assistant in nuclear engineering and physics--studied an important class of complex metal oxides.
The materials, each consisting of two or more positively charged metal ions and oxygen, are used in a wide range of applications including fast ion conductors in solid oxide fuel cells, host materials for nuclear waste containment, and thermal barrier coatings for gas turbine jet engines.
For their study, the team used state-of-the-art neutron characterization techniques to gain a detailed understanding and new insights into the nature of the atomic motifs in these materials. The work was published in the journal Nature Materials on February 29.
"The complex oxides we analyzed in this study--pyrochlore and spinel--have been investigated for decades by different researchers," said Lang. "When subjected to extreme environments such as high temperatures or high-energy radiation, many of these compounds partially lose their long-range crystal structure, and the multiple cations were thought to randomly exchange crystal sites."
Lang said the multidisciplinary research team and the unique capabilities of ORNL's Spallation Neutron Source, a DOE Office of Science User Facility, helped the team discover a novel atomic disordering mechanism in these materials.
With the help of SNS instrument scientists Mikhail Feygenson and Joerg Neuefeind, Lang and his team used the Nanoscale-Ordered Materials Diffractometer (NOMAD) for an in-depth look at the local crystal structure of their samples--a NOMAD first for neutron scattering experiments on ion-irradiated materials.
Neutrons are indispensable for this type of study because they can accurately detect the position of oxygen atoms present in materials.
"Using neutrons to measure samples of such small sizes would have been difficult, if not impossible, just a few years ago," said Feygenson. "However, with the combination of the high neutron flux of SNS and the wide detector coverage of the NOMAD instrument, scientists can look at very small samples, which are typically the domain of X-ray scattering experiments."
Data analysis from NOMAD revealed the cations and oxygens in the materials are not randomly arranged at the atomic level but only appear so when sampling over longer scales, a key discovery.
Lang said the heterogeneous disorder was unexpected but seems to be a general phenomenon for many other materials functioning in harsh conditions. He said the new insight into disorder is fundamental to controlling oxygen mobility and phonon transport in complex oxides, a critical aspect for technological applications.
By gaining a better understanding of such materials, the team could help improve and control performance across a range of technologies--containment and immobilization of nuclear waste being a prime example.
"This ability to accommodate atomic disorder in their structure accounts for the tendency of some compositions to resist becoming fully amorphous under irradiation or at high temperatures," Lang said. "Such materials find application as host materials for immobilizing actinides, such as plutonium.
"Predicting transport of radionuclides is important for their safe use as nuclear waste forms and requires a detailed knowledge of how the atomic structure responds to self-irradiation."
Lang said the team's data will provide much needed atomic-scale information from the initial local defect structure to the long-range observable material modifications so that waste form properties and degradation can be accurately simulated.
###
Other researchers on the team included Cameron Tracy and Rodney Ewing of Stanford University, Fuxiang Zhang of the University of Michigan, and Sarah Finkeldei and Dirk Bosbach of the Forschungszentrum Jülich Institute of Energy and Climate Research in Germany.
The work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by DOE's Office of Science.
####
About Oak Ridge National Laboratory
UT-Battelle manages ORNL for DOE's Office of Science. The single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time.--By David Goddard, UT
For more information, please click here
Contacts:
Jeremy Rumsey
865-576-2038
Copyright © Oak Ridge National Laboratory
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Related News Press |
News and information
Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025
Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025
Laboratories
A battery’s hopping ions remember where they’ve been: Seen in atomic detail, the seemingly smooth flow of ions through a battery’s electrolyte is surprisingly complicated February 16th, 2024
NRL discovers two-dimensional waveguides February 16th, 2024
Govt.-Legislation/Regulation/Funding/Policy
Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025
Quantum engineers ‘squeeze’ laser frequency combs to make more sensitive gas sensors January 17th, 2025
Chainmail-like material could be the future of armor: First 2D mechanically interlocked polymer exhibits exceptional flexibility and strength January 17th, 2025
Discoveries
Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025
Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025
Materials/Metamaterials/Magnetoresistance
Chainmail-like material could be the future of armor: First 2D mechanically interlocked polymer exhibits exceptional flexibility and strength January 17th, 2025
Enhancing transverse thermoelectric conversion performance in magnetic materials with tilted structural design: A new approach to developing practical thermoelectric technologies December 13th, 2024
FSU researchers develop new methods to generate and improve magnetism of 2D materials December 13th, 2024
Announcements
Closing the gaps — MXene-coating filters can enhance performance and reusability February 28th, 2025
Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Leading the charge to better batteries February 28th, 2025
Quantum interference in molecule-surface collisions February 28th, 2025
New ocelot chip makes strides in quantum computing: Based on "cat qubits," the technology provides a new way to reduce quantum errors February 28th, 2025
Energy
KAIST researchers introduce new and improved, next-generation perovskite solar cell November 8th, 2024
Unveiling the power of hot carriers in plasmonic nanostructures August 16th, 2024
Groundbreaking precision in single-molecule optoelectronics August 16th, 2024
Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024
Aerospace/Space
Flexible electronics integrated with paper-thin structure for use in space January 17th, 2025
The National Space Society Congratulates SpaceX on Starship’s 7th Test Flight: Latest Test of the Megarocket Hoped to Demonstrate a Number of New Technologies and Systems January 17th, 2025
Bringing the power of tabletop precision lasers for quantum science to the chip scale December 13th, 2024
Fuel Cells
Current and Future Developments in Nanomaterials and Carbon Nanotubes: Applications of Nanomaterials in Energy Storage and Electronics October 28th, 2022
Research partnerships
SMART researchers pioneer first-of-its-kind nanosensor for real-time iron detection in plants February 28th, 2025
Gene therapy relieves back pain, repairs damaged disc in mice: Study suggests nanocarriers loaded with DNA could replace opioids May 17th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
![]() |
||
![]() |
||
The latest news from around the world, FREE | ||
![]() |
![]() |
||
Premium Products | ||
![]() |
||
Only the news you want to read!
Learn More |
||
![]() |
||
Full-service, expert consulting
Learn More |
||
![]() |