A foundation that fits just right gives superconducting nickelates a
boost
It irons out wrinkles in thin films of these novel superconductors so scientists can see their true nature for the first time

Date:
July 12, 2023
Source:
DOE/SLAC National Accelerator Laboratory
Summary:
Researchers made thin films of an exciting new nickel oxide
superconductor that are free of extended defects. This improved
the material's ability to conduct electricity with no loss and
gave them the first clear view of its properties. They discovered
that this nickelate is more like the superconducting cuprates than
previously thought.


Facebook Twitter Pinterest LinkedIN Email

==========================================================================
FULL STORY ========================================================================== Researchers at the Department of Energy's SLAC National Accelerator
Laboratory and Stanford University say they've found a way to make thin
films of an exciting new nickel oxide superconductor that are free of
extended defects.

Not only does this improve the material's ability to conduct electricity
with no loss, they said, but it also allows them to discover its true
nature and properties, both in and out of the superconducting state,
for the first time.

Their first look at a superconducting nickel oxide, or nickelate,
that does not have defects revealed that it is more like the cuprates
- which hold the world's high-temperature record for unconventional superconductivity at normal pressures -- than previously thought. For
instance, when the nickelate is tweaked to optimize its superconductivity
and then heated above its superconducting temperature, its resistance
to the flow of electric current increases in a linear fashion, just as
in cuprates.

Those striking similarities, they said, may mean these two very different materials achieve superconductivity in much the same way.

It's the latest step in a 35-year quest to develop superconductors that
can operate at close to room temperature, which would revolutionize electronics, transportation, power transmission and other technologies
by allowing them to operate without energy-wasting electrical resistance.

The research team, led by Harold Hwang, director of the Stanford Institute
for Materials and Energy Sciences (SIMES) at SLAC, described their work
today in the journal Nature.

"Nickelate films are really unstable, and until now our efforts to
stabilize them on top of other materials have produced defects that are
like speed bumps for electrons," said Kyuho Lee, a SIMES postdoctoral researcher who contributed to the discovery of superconductivity in
nickelates four years ago and has been working on them ever since.

"These quality issues have led to many debates and open questions about nickelate properties, with research groups reporting widely varying
results," Lee said. "So eliminating the defects is a significant
breakthrough. It means we can finally address the underlying physics
behind these materials and behind unconventional superconductivity
in general." Jenga chemistry and a just-right fit The defects, which
are a bit like misaligned zipper teeth, arise from the same innovative
process that allowed Hwang's team to create and stabilize a nickelate
film in the first place.

They started by making a common material known as perovskite. They
"doped" it to change its electrical conductivity, then exposed it to a
chemical that deftly removed layers of oxygen atoms from its molecular structure, much like removing a stick from a tower of Jenga blocks. With
the oxygen layers gone, the film settled into a new structure -- known
as an infinite-layer nickelate -that can host superconductivity.

The atomic latticework of this new structure occupied a slightly bigger
surface area than the original. With this in mind, they had built the
film on a foundation, or substrate, that would be a good fit for the
finished, spread-out product, Lee said.

But it didn't match the atomic lattice of the starting material, which developed defects as it tried to fit comfortably onto the substrate --
and those imperfections carried through to the finished nickelate.

Hwang said it's as if two friends of different sizes had to share a
coat. If the coat fit the smaller friend perfectly, the larger one would
have a hard time zipping it up. If it fit the larger friend perfectly,
it would hang like a tent on the smaller one and let the cold in. An
in-between size might not be the best fit for either of them, but it's
close enough to keep them both warm and happy.

That's the solution Lee and his colleagues pursued.

In a series of meticulous experiments, they used a substrate that was
like the in-between coat. The atomic structure of its surface was a
close enough fit for both the starting and ending materials that the
finished nickelate came out defect-free. Lee said the team is already
starting to see some interesting physics in the nickelate now that the
system is much cleaner.

"What this means," Hwang said, "is that we are getting closer and
closer to measuring the intrinsic properties of these materials. And
by sharing the details of how to make defect-free nickelates, we hope
to benefit the field as a whole." Researchers from Cornell University contributed to this work, which was funded by the DOE Office of Science
and the Gordon and Betty Moore Foundation's Emergent Phenomena in Quantum Systems Initiative.

* RELATED_TOPICS
o Matter_&_Energy
# Physics # Materials_Science # Energy_Technology #
Quantum_Physics
o Computers_&_Math
# Spintronics_Research # Computer_Science # Communications
* RELATED_TERMS
o Periodic_table o Nickel o Noble_gas o Raney_nickel o
Triboelectric_effect o Fullerene o Metal o Robot

==========================================================================

Print

Email

Share ========================================================================== ****** 1 ****** ***** 2 ***** **** 3 ****
*** 4 *** ** 5 ** Breaking this hour ==========================================================================
* Salinity_Changes_Threatening_Marine_Ecosystems *
Plastic_Pollution_On_Reefs_Mostly_from_Fishing
* Detailed_Map_of_the_Heart *
Microplastics_Contamination_in_Lakes_and_...

* Diverse_Organic_Material_On_Mars *
How_the_Immune_System_Can_Alter_Our_Behavior *
Ocean's_Color_Is_Changing_Due_to_Climate_Change *
Start_of_Anthropocene_Epoch:_Canadian_Lake_...

* Pump_Powers_Soft_Robots,_Makes_Cocktails *
Rat_Poison_--_Neurotoxicant_--_In_Birds_of_Prey

Trending Topics this week ========================================================================== SPACE_&_TIME Mars Space_Missions Big_Bang MATTER_&_ENERGY
Nature_of_Water Civil_Engineering Medical_Technology COMPUTERS_&_MATH Artificial_Intelligence Robotics Neural_Interfaces


==========================================================================

Strange & Offbeat ========================================================================== SPACE_&_TIME
New_Study_Reveals_Evidence_of_Diverse_Organic_Material_on_Mars Training_Robots_How_to_Learn,_Make_Decisions_on_the_Fly Reinventing_Cosmology:_New_Research_Puts_Age_of_Universe_at_26.7_--_Not_13.7_- -_Billion_Years MATTER_&_ENERGY Pump_Powers_Soft_Robots,_Makes_Cocktails Capturing_the_Immense_Potential_of_Microscopic_DNA_for_Data_Storage Revolutionary_Self-Sensing_Electric_Artificial_Muscles COMPUTERS_&_MATH Bees_Make_Decisions_Better_and_Faster_Than_We_Do,_for_the_Things_That_Matter_to Them Number_Cruncher_Calculates_Whether_Whales_Are_Acting_Weirdly AI_Tests_Into_Top_1%_for_Original_Creative_Thinking Story Source:
Materials provided by DOE/SLAC_National_Accelerator_Laboratory. Original written by Glennda Chui. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Kyuho Lee, Bai Yang Wang, Motoki Osada, Berit H. Goodge, Tiffany
C. Wang,
Yonghun Lee, Shannon Harvey, Woo Jin Kim, Yijun Yu,
Chaitanya Murthy, Srinivas Raghu, Lena F. Kourkoutis, Harold
Y. Hwang. Linear-in- temperature resistivity for optimally
superconducting (Nd,Sr)NiO2.

Nature, 2023; 619 (7969): 288 DOI: 10.1038/s41586-023-06129-x ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/07/230712124614.htm

--- up 1 year, 19 weeks, 2 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)