Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Aug. 27, 2024
Abstract
A
key
open
question
in
the
study
of
layered
superconducting
nickelate
films
is
role
that
hydrogen
incorporation
into
lattice
plays
appearance
state.
Due
to
challenges
stabilizing
highly
crystalline
square
planar
films,
are
prepared
by
deposition
a
more
stable
parent
compound
which
then
transformed
target
phase
via
topotactic
reaction
with
strongly
reducing
agent
such
as
CaH
2
.
Recent
studies,
both
experimental
and
theoretical,
have
introduced
possibility
from
may
be
critical
for
superconductivity.
In
this
work,
we
use
secondary
ion
mass
spectrometry
examine
La
1−
x
X
NiO
/
SrTiO
3
(
=
Ca
Sr)
Nd
6
Ni
5
O
12
NdGaO
along
non-superconducting
NdNiO
(Nd,Sr)NiO
We
find
no
evidence
extensive
across
broad
range
samples,
including
films.
Theoretical
calculations
indicate
broadly
energetically
unfavorable
these
systems,
supporting
our
conclusion
not
generally
required
achieve
state
square-planar
nickelates.
Using
ab
initio
band
structure
and
$\mathrm{DFT}+\mathrm{dynamical}$
mean-field
theory
methods
we
examine
the
effects
of
electron-electron
interactions
on
normal
state
electronic
structure,
Fermi
surface,
magnetic
correlations
recently
discovered
double-layer
perovskite
superconductor
${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$
under
pressure.
Our
results
suggest
formation
a
negative
charge
transfer
mixed-valence
with
Ni
valence
close
to
$1.75+$.
We
find
remarkable
orbital-selective
renormalization
$3d$
bands,
${m}^{*}/m\ensuremath{\sim}3$
2.3
for
$3{z}^{2}\text{\ensuremath{-}}{r}^{2}$
${x}^{2}\text{\ensuremath{-}}{y}^{2}$
orbitals,
respectively,
in
agreement
experimental
estimates.
$k$-dependent
spectral
functions
surfaces
show
significant
incoherence
states,
implying
proximity
states
orbital-dependent
localization.
Based
our
analysis
static
susceptibility,
propose
possible
spin
(or
bond)
density
wave
stripe
high-pressure
${\mathrm{La}}_{3}{\mathrm{Ni}}_{2}{\mathrm{O}}_{7}$.
Chinese Physics Letters,
Journal Year:
2023,
Volume and Issue:
41(1), P. 017401 - 017401
Published: Dec. 14, 2023
The
discovery
of
high-temperature
superconductivity
near
80
K
in
bilayer
nickelate
La
3
Ni
2
O
7
under
high
pressures
has
renewed
the
exploration
superconducting
bulk
materials.
extension
other
nickelates
a
broader
family
is
also
essential.
Here,
we
report
experimental
observation
signature
trilayer
4
10
pressures.
By
using
modified
sol-gel
method
and
post-annealing
treatment
oxygen
pressure,
successfully
obtained
polycrystalline
samples
with
different
transport
behaviors
at
ambient
pressure.
Then
performed
high-pressure
electrical
resistance
measurements
on
these
diamond-anvil-cell
apparatus.
Surprisingly,
possible
transition
maximum
temperature
(
T
c
)
about
20
observed,
as
evidenced
by
clear
drop
suppression
drops
magnetic
fields.
Although
sample-dependent
relatively
small,
it
appears
all
our
measured
samples.
We
argue
that
observed
signal
most
likely
to
originate
from
main
phase
.
Our
findings
will
motivate
shed
light
understanding
underlying
mechanisms
high-
nickelates.
Nanoscale,
Journal Year:
2024,
Volume and Issue:
16(9), P. 4352 - 4377
Published: Jan. 1, 2024
The
review
highlights
charge
transfer,
improved
photocatalytic
performance,
and
possible
photocatalysis
schemes
in
TiO
2
-based
composites.
It
also
addresses
perspectives
challenges
transfer
mechanisms
for
photocatalysis.
The
search
for
a
novel
superconductor
exhibiting
high
critical
temperature
(high
${T}_{c}$)
or
even
near
room
at
an
accessible
synthetic
pressure
is
persistent
objective
both
experimental
and
theoretical
physicists.
Here,
we
conduct
systematic
high-throughput
structure
on
boron-carbon
clathrates
ambient
uncover
two
stable
1166-type
superconductors,
${\mathrm{RbYbB}}_{6}{\mathrm{C}}_{6}$
${\mathrm{RbBaB}}_{6}{\mathrm{C}}_{6}$,
maximum
${T}_{c}\ensuremath{\sim}70$
K.
high-${T}_{c}$
superconductivity
in
superconductors
attributed
to
key
factors:
enhanced
density
of
states
the
Fermi
level
strong
B-C
covalent
framework
clathrates,
which
enhance
electron-phonon
coupling
facilitate
temperatures
boiling
point
liquid
nitrogen.
These
results
provide
significant
advancement
understanding
underlying
mechanisms
based
offer
valuable
avenues
design
synthesis
advanced
high-temperature
conditions.
Science Advances,
Journal Year:
2023,
Volume and Issue:
9(27)
Published: July 5, 2023
We
report
on
superconductivity
in
Nd
1−
x
Eu
NiO
2
using
as
a
4f
dopant
of
the
parent
NdNiO
infinite-layer
compound.
use
an
all–in
situ
molecular
beam
epitaxy
reduction
process
to
achieve
superconducting
phase,
providing
alternate
method
ex
CaH
induce
nickelates.
The
samples
exhibit
step-terrace
structure
their
surfaces,
have
T
c
onset
21
K
at
=
0.25,
and
large
upper
critical
field
that
may
be
related
doping.
Journal of Physics D Applied Physics,
Journal Year:
2024,
Volume and Issue:
57(19), P. 193001 - 193001
Published: Feb. 2, 2024
Abstract
Molecular
beam
epitaxy
(MBE),
a
workhorse
of
the
semiconductor
industry,
has
progressed
rapidly
in
last
few
decades
development
novel
materials.
Recent
developments
condensed
matter
and
materials
physics
have
seen
rise
many
quantum
that
require
ultra-clean
high-quality
samples
for
fundamental
studies
applications.
Novel
oxide-based
synthesized
using
MBE
advanced
field
In
this
review,
we
discuss
recent
progress
new
techniques
enabled
synthesis
complex
oxides
exhibit
‘quantum’
phenomena,
including
superconductivity
topological
electronic
states.
We
show
how
these
produced
breakthroughs
4d
5d
oxide
films
heterostructures
are
particular
interest
as
These
offer
bright
future
ultra-high
quality
