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

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Imaging

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Lightweight metal foams become bone hard and explosion proof after being nanocoated March 14th, 2019

New optical imaging system could be deployed to find tiny tumors: Near-infrared technology pinpoints fluorescent probes deep within living tissue; may be used to detect cancer earlier March 8th, 2019

New blueprint for understanding, predicting and optimizing complex nanoparticles: Guidelines have the potential to transform the fields of optoelectronics, bio-imaging and energy harvesting March 1st, 2019

Flipping the view: New microscope offers options for drug discovery, safety and effectiveness February 28th, 2019

Laboratories

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

Govt.-Legislation/Regulation/Funding/Policy

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Possible Futures

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Chip Technology

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Pushing Past Limits: Junkai Jiang receives prestigious Ph.D. Student Fellowship from IEEE Electron Devices Society March 14th, 2019

Nanometrics Announces $80 Million Share Repurchase Program March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Discoveries

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Review of the recent advances of 2D nanomaterials in Lit-ion batteries March 15th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Materials/Metamaterials

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Now made in Japan – Asian battery manufacturers welcome highly conductive nanotube additive March 7th, 2019

Can a flowing liquid-like material maintain its structural order like crystals? February 27th, 2019

Super-light, super-insulating ceramic aerogel keeps the hottest temperatures at bay February 17th, 2019

Announcements

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

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

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Review of the recent advances of 2D nanomaterials in Lit-ion batteries March 15th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Military

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Lightweight metal foams become bone hard and explosion proof after being nanocoated March 14th, 2019

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