Unconventional Crystal Structure of the High-Pressure Superconductor La3Ni2O7
Physical Review Letters,
Год журнала:
2024,
Номер
133(14)
Опубликована: Окт. 4, 2024
The
discovery
of
high-temperature
superconductivity
in
La3Ni2O7
at
pressures
above
14
GPa
has
spurred
extensive
research
efforts.
Yet,
fundamental
aspects
the
superconducting
phase,
including
possibility
a
filamentary
character,
are
currently
subjects
controversial
debates.
Conversely,
crystal
structure
with
NiO6
octahedral
bilayers
stacked
along
c-axis
direction
was
consistently
posited
initial
studies
on
La3Ni2O7.
Here,
we
reassess
this
optical
floating
zone-grown
La3Ni2O7
single
crystals
that
show
signs
superconductivity.
Employing
scanning
transmission
electron
microscopy
and
single-crystal
x-ray
diffraction
under
high
pressures,
observe
multiple
crystallographic
phases
these
crystals,
majority
phase
exhibiting
alternating
monolayers
trilayers
NiO6
octahedra,
signifying
profound
deviation
from
previously
suggested
bilayer
structure.
Using
density
functional
theory,
disentangle
individual
contributions
monolayer
trilayer
structural
units
to
electronic
band
La3Ni2O7,
providing
firm
basis
for
advanced
theoretical
modeling
future
evaluations
potential
monolayer-trilayer
hosting
Published
by
American
Physical
Society
2024
Язык: Английский
Self-powered ultraviolet position-sensitive detectors based on PrNiO3/Nb-doped SrTiO3 p–n junctions
Applied Physics Letters,
Год журнала:
2025,
Номер
126(2)
Опубликована: Янв. 13, 2025
Position-sensitive
detectors
based
on
the
lateral
photovoltaic
effect
have
been
widely
used
in
optical
engineering
for
measurement
of
position,
distance,
and
angles.
However,
self-powered
ultraviolet
position-sensitive
with
high
sensitivity
fast
response
are
still
lacking
due
to
difficulty
associated
fabrication
p-type
wide
bandgap
semiconductors,
which
hinders
their
further
design
enhancement.
Here,
influence
band
structures
interfacial
transport
properties
performance
PrNiO3/Nb:SrTiO3p–n
junctions
is
systematically
investigated.
Large
position
relaxation
time
were
observed
up
400
K
perovskite-based
detectors.
Hall
measurements
revealed
that
photoexcited
carriers
occurs
mainly
through
interface
PrNiO3/Nb:SrTiO3
junctions,
resulting
a
stable
effect.
This
study
presents
insights
avenues
designing
perovskite
oxide
enhanced
photoelectric
performance.
Язык: Английский
Three generations of infinite-layer nickelate crystals
MRS Communications,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 3, 2025
Язык: Английский
Investigation of spin excitations and charge order in bulk crystals of the infinite-layer nickelate LaNiO2
Physical review. B./Physical review. B,
Год журнала:
2024,
Номер
109(23)
Опубликована: Июнь 3, 2024
Recent
x-ray
spectroscopic
studies
have
revealed
spin
excitations
and
charge
density
waves
in
thin
films
of
infinite-layer
(IL)
nickelates.
However,
clarifying
whether
the
origin
these
phenomena
is
intrinsic
to
material
class
or
attributable
impurity
phases
has
presented
a
major
challenge.
Here
we
utilize
topotactic
methods
synthesize
bulk
crystals
IL
nickelate
LaNiO2
with
crystallographically
oriented
surfaces.
We
examine
using
resonant
inelastic
scattering
(RIXS)
at
Ni
L3-edge
elucidate
correlations
material.
While
detect
presence
prominent
crystals,
fingerprints
order
are
absent
ordering
vectors
identified
previous
thin-film
studies.
These
results
contribute
understanding
properties
LaNiO2
establish
topotactically
synthesized
as
viable
complementary
specimens
for
investigations.
Published
by
American
Physical
Society
2024
Язык: Английский
Realization of a classical Ruddlesden Popper type bilayer nickelate in Sr3Ni2−xAlxO7−δ with unusual Ni4+
npj Quantum Materials,
Год журнала:
2024,
Номер
9(1)
Опубликована: Ноя. 22, 2024
Abstract
The
discovery
of
80
K
superconductivity
in
bilayer
La
3
Ni
2
O
7
at
pressures
greater
than
14
GPa
presents
a
unique
opportunity
to
study
novel
class
high-temperature
superconductors.
Therefore,
other
nickelates
following
the
classical
(
T
4+
)
Ruddlesden-Popper
(RP)
series
Sr
would
present
an
interesting
new
candidate.
In
this
work,
we
stabilization
RP
n
=
phase
2−
x
Al
7−
δ
,
via
floating
zone
growth
crystals.
With
powder
and
single-crystal
XRD,
stability
range
RP-type
phase.
Our
Thermogravimetric
Analysis
(TGA),
X-ray
photoelectron
spectroscopy
(XPS)
gas
extraction
studies
reveal
remarkably
high
oxidation
state
stabilized
by
chemical
strain
from
Al.
obtained
black
crystals
are
insulating
transport
show
magnetic
transition
around
12
K.
Язык: Английский
Unraveling nano-scale effects of topotactic reduction in LaNiO2 crystals
APL Materials,
Год журнала:
2024,
Номер
12(9)
Опубликована: Сен. 1, 2024
Infinite-layer
nickelates
stand
as
a
promising
frontier
in
the
exploration
of
unconventional
superconductivity.
Their
synthesis
through
topotactic
oxygen
reduction
from
parent
perovskite
phase
remains
complex
and
elusive
process.
This
study
delves
into
nano-scale
effects
lattice
transformation
within
LaNiO2
crystals.
Leveraging
high-resolution
scanning
transmission
electron
microscopy
spectroscopy,
our
investigations
uncover
panorama
structural
alterations,
including
grain
boundaries
coherent
twin
boundaries,
triggered
by
reduction-induced
transformations.
In
addition,
analyses
unveil
formation
an
oxygen-rich
disordered
transition
encircling
impurities
pervading
crystalline
domains
internal
strain
is
accommodated
boundary
formation.
By
unraveling
these
effects,
findings
provide
insights
microscopic
intricacies
process
elucidating
to
infinite-layer
nickelate
bulk
Язык: Английский