Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Unlocking the Secrets of Metal-Insulator Transitions: X-ray photon correlation spectroscopy at NSLS-II's CSX beamline used to understand electrical conductivity transitions in magnetite

Professor Roopali Kukreja from the University of California in Davis and the CSX team Wen Hu, Claudio Mazzoli, and Andi Barbour prepare the beamline for the next set of experiments.
Professor Roopali Kukreja from the University of California in Davis and the CSX team Wen Hu, Claudio Mazzoli, and Andi Barbour prepare the beamline for the next set of experiments.

Abstract:
By using an x-ray technique available at the National Synchrotron Light Source II (NSLS-II), scientists found that the metal-insulator transition in the correlated material magnetite is a two-step process. The researchers from the University of California Davis published their paper in the journal Physical Review Letters [ https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.177601 ]. NSLS-II, a U.S. Department of Energy (DOE) Office of Science user facility located at Brookhaven National Laboratory, has unique features that allow the technique to be applied with stability and control over long periods of time.

Unlocking the Secrets of Metal-Insulator Transitions: X-ray photon correlation spectroscopy at NSLS-II's CSX beamline used to understand electrical conductivity transitions in magnetite

Upton, NY | Posted on November 8th, 2018

"Correlated materials have interesting electronic, magnetic, and structural properties, and we try to understand how those properties change when their temperature is changed or under the application of light pulses, or an electric field" said Roopali Kukreja, a UC Davis professor and the lead author of the paper. One such property is electrical conductivity, which determines whether a material is metallic or an insulator.

If a material is a good conductor of electricity, it is usually metallic, and if it is not, it is then known as an insulator. In the case of magnetite, temperature can change whether the material is a conductor or insulator. For the published study, the researchers' goal was to see how the magnetite changed from insulator to metallic at the atomic level as it got hotter.

In any material, there is a specific arrangement of electrons within each of its billions of atoms. This ordering of electrons is important because it dictates a material's properties, for example its conductivity. To understand the metal-insulator transition of magnetite, the researchers needed a way to watch how the arrangement of the electrons in the material changed with the alteration of temperature.

"This electronic arrangement is related to why we believe magnetite becomes an insulator," said Kukreja. However, studying this arrangement and how it changes under different conditions required the scientists to be able to look at the magnetite at a super-tiny scale.

The technique, known as x-ray photon correlation spectroscopy (XPCS), available at NSLS-II's Coherent Soft X-ray scattering (CSX) beamline [https://www.bnl.gov/ps/beamlines/beamline.php?r=23-ID-1], allowed the researchers to look at how the material changed at the nanoscale—on the order of billionths of a meter.

"CSX is designed for soft x-ray coherent scattering. This means that the beamline exploits our ultrabright, stable and coherent source of x-rays to analyze how the electron's arrangement changes over time," explained Andi Barbour, a CSX scientist who is a coauthor on the paper. "The excellent stability allows researchers to investigate tiny variations over hours so that the intrinsic electron behavior in materials can be revealed."

However, this is not directly visible so XPCS uses a trick to reveal the information.

"The XPCS technique is a coherent scattering method capable of probing dynamics in a condensed matter system. A speckle pattern is generated when a coherent x-ray beam is scattered from a sample, as a fingerprint of its inhomogeneity in real space," said Wen Hu, a scientist at CSX and co-author of the paper.

Scientists can then apply different conditions to their material and if the speckle pattern changes, it means the electron ordering in the sample is changing. "Essentially, XPCS measures how much time it takes for a speckle's intensity to become very different from the average intensity, which is known as decorrelation," said Claudio Mazzoli, the lead beamline scientist at the CSX beamline. "Considering many speckles at once, the ensemble decorrelation time is the signature of the dynamic timescale for a given sample condition."

The technique revealed that the metal-insulator transition is not a one step process, as was previously thought, but actually happens in two steps.

"What we expected was that things would go faster and faster while warming up. What we saw was that things get faster and faster and then they slow down. So the fast phase is one step and the second step is the slowing down, and that needs to happen before the material becomes metallic," said Kukreja. The scientists suspect that the slowing down occurs because, during the phase change, the metallic and insulating properties actually exist at the same time in the material.

"This study shows that these nanometer length scales are really important for these materials," said Kukreja. "We can't access this information and these experimental parameters anywhere else than at the CSX beamline of NSLS-II."

This research was funded by the National Science Foundation, the Air Force Office of Scientific Research, and the University of California's Multicampus Research Programs and Initiatives.

Written by Allison Gasparini

####

About Brookhaven National Laboratory
Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov [https://science.energy.gov/].

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit applied science and technology organization.

Follow @brookhavenlab on Twitter and Facebook

For more information, please click here

Contacts:
Peter Genzer [ ], (631) 344-3174,
or Karen McNulty Walsh [ ], (631) 344-8350

Copyright © Brookhaven 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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Scientific Paper: "Orbital Domain Dynamics in Magnetite below the Verwey Transition":

Related News Press

News and information

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

Imaging

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

Tiny light detectors work like gecko ears October 30th, 2018

Light-bending tech shrinks kilometers-long radiation system to millimeter scale October 26th, 2018

Laboratories

Nanotech Artisans Sculpt with DNA November 5th, 2018

Leti and Taiwanese National Applied Research Laboratories Announce Collaboration for Microelectronics Innovation: Collaboration Will Facilitate Scientific and Technological Exchanges in Microelectronics, Sharing Platforms and Encouraging PhD Student Exchanges October 23rd, 2018

Govt.-Legislation/Regulation/Funding/Policy

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

European Commission Project Creates Pilot Line for Companies to Develop Mid-Infrared Devices: Companies Can Submit Proposals for Possible Matching Funds To Help Develop Prototypes November 13th, 2018

Physicists name and codify new field in nanotechnology: ‘electron quantum metamaterials:’ UC Riverside’s Nathaniel Gabor and colleague formulate a vision for the field in a perspective article November 5th, 2018

Nanotech Artisans Sculpt with DNA November 5th, 2018

Possible Futures

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

Arrowhead Pharmaceuticals Presents Late-Breaking Preliminary Clinical Data on ARO-HBV at Liver Meeting® 2018 November 9th, 2018

The National Graphene Association Is Excited To Announce A New Affiliate Partnership With Graphene Engineering Innovation Centre (GEIC) November 7th, 2018

Chip Technology

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

IEDM - CEA-Leti Will Present 11 Papers and Host Workshop on Disruptive Technologies for Data Management November 7th, 2018

Discoveries

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

WSU researchers develop new technique to understand biology at the nanoscale November 7th, 2018

A record-long polymer DNA negative November 6th, 2018

Materials/Metamaterials

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

Physicists name and codify new field in nanotechnology: ‘electron quantum metamaterials:’ UC Riverside’s Nathaniel Gabor and colleague formulate a vision for the field in a perspective article November 5th, 2018

Eco-friendly waterproof polymer films synthesized using novel method October 31st, 2018

Rice U. scientists form flat tellurium: Two-dimensional element shows promise for solar cells and other optoelectronics October 26th, 2018

Announcements

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

GLOBALFOUNDRIES, indie Semiconductor Deliver Performance-Enhanced Microcontrollers for Automotive Applications: 55nm LPx platform, with SST’s highly reliable embedded SuperFlash®, increases performance and energy efficiency for automotive applications November 13th, 2018

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Optimization of alloy materials: Diffusion processes in nano particles decoded November 13th, 2018

WSU researchers develop new technique to understand biology at the nanoscale November 7th, 2018

IEDM - CEA-Leti Will Present 11 Papers and Host Workshop on Disruptive Technologies for Data Management November 7th, 2018

Military

Epoxy compound gets a graphene bump: Rice scientists combine graphene foam, epoxy into tough, conductive composite November 14th, 2018

Physicists name and codify new field in nanotechnology: ‘electron quantum metamaterials:’ UC Riverside’s Nathaniel Gabor and colleague formulate a vision for the field in a perspective article November 5th, 2018

A bullet-proof heating pad November 2nd, 2018

Tiny light detectors work like gecko ears October 30th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project