Introducing
compositional
or
structural
disorder
within
crystalline
solid
electrolytes
is
a
common
strategy
for
increasing
their
ionic
conductivity.
(M,Sn)F2
fluorites
have
previously
been
proposed
to
exhibit
two
forms
of
cationic
host
frameworks:
occupational
from
randomly
distributed
M
and
Sn
cations,
orientational
Sn(II)
stereoactive
lone
pairs.
Here,
we
characterise
the
structure
fluoride-ion–dynamics
cubic-BaSnF4,
using
combination
experimental
computational
techniques.
Rietveld
refinement
XRD
data
confirms
an
average
fluorite
with
{Ba,Sn}
cation
disorder,
119Sn
Mo
̈ssbauer
spectrum
demonstrates
presence
X-ray
total-scattering
PDF
analysis
ab
initio
molecular
dynamics
simulations
reveal
complex
local
high
degree
intrinsic
fluoride-ion
where
1/3
fluoride
ions
occupy
octahedral
“interstitial”
sites:
this
consequence
repulsion
between
pairs
that
destabilises
Sn-coordinated
tetrahedral
sites.
Variable-temperature
19F
NMR
experiments
our
highly
inhomogeneous
dynamics,
in
Sn-rich
environments
significantly
more
mobile
than
those
Ba-rich
environments.
Our
also
dynamical
reorientation
biased
by
configuration
coupled
dynamics.
We
end
discussing
effect
host-framework
on
long-range
diffusion
pathways
cubic
BaSnF4
.
npj Computational Materials,
Год журнала:
2024,
Номер
10(1)
Опубликована: Фев. 26, 2024
Abstract
Machine
learning
interatomic
potentials
(MLIPs)
enable
accurate
simulations
of
materials
at
scales
beyond
that
accessible
by
ab
initio
methods
and
play
an
increasingly
important
role
in
the
study
design
materials.
However,
MLIPs
are
only
as
robust
data
on
which
they
trained.
Here,
we
present
DImensionality-Reduced
Encoded
Clusters
with
sTratified
(DIRECT)
sampling
approach
to
select
a
training
set
structures
from
large
complex
configuration
space.
By
applying
DIRECT
Materials
Project
relaxation
trajectories
dataset
over
one
million
89
elements,
develop
improved
3-body
graph
network
(M3GNet)
universal
potential
extrapolates
more
reliably
unseen
structures.
We
further
show
molecular
dynamics
(MD)
M3GNet
can
be
used
instead
expensive
MD
rapidly
create
space
for
target
systems.
combined
this
scheme
reliable
moment
tensor
titanium
hydrides
without
need
iterative
augmentation
This
work
paves
way
high-throughput
development
across
any
compositional
complexity.
Science Bulletin,
Год журнала:
2024,
Номер
69(22), С. 3525 - 3532
Опубликована: Сен. 1, 2024
This
study
introduces
a
novel
AI
force
field,
namely
graph-based
pre-trained
transformer
field
(GPTFF),
which
can
simulate
arbitrary
inorganic
systems
with
good
precision
and
generalizability.
Harnessing
large
trove
of
the
data
attention
mechanism
algorithms,
model
accurately
predict
energy,
atomic
forces,
stress
Mean
Absolute
Error
(MAE)
values
32
meV/atom,
71
meV/{\AA},
0.365
GPa,
respectively.
The
dataset
used
to
train
includes
37.8
million
single-point
energies,
11.7
billion
pairs,
340.2
stresses.
We
also
demonstrated
that
GPTFF
be
universally
various
physical
systems,
such
as
crystal
structure
optimization,
phase
transition
simulations,
mass
transport.
Advanced Materials,
Год журнала:
2024,
Номер
36(16)
Опубликована: Янв. 27, 2024
Abstract
In
superionic
crystals,
liquid‐like
ionic
diffusivities
often
come
hand‐in‐hand
with
ultra‐low
thermal
conductivity
and
soft
vibrational
dynamics.
However,
generalized
relationships
between
ion
transport
dynamics
remain
elusive
due
to
the
diversity
of
materials
complex
underlying
mechanisms.
Here,
links
in
close‐packed
lithium
halide
conductor
Li
3
YCl
6
(LYC)
are
examined
using
a
suite
atomistic
first‐principles
methods.
It
is
shown
that
configurational
disorder,
lattice
anharmonicity,
coupled
host‐mobile
together
induce
transition
state.
Statistical
correlations
hops
activation
distribution
modes
found.
typical
phenomena
associated
conductors
such
as
selective
breakdown
zone‐boundary
phonons,
or
long
wavelength
transverse
acoustic
‘phonon‐liquid‐electron
crystal’
concept,
not
present.
Instead,
anharmonic
aiding
diffusion
found
broaden
soften
selectively
but
persist
across
transition.
These
couple
motion
vibrations
flexible
anion
framework,
which
remains
stable
facilitates
hopping.
The
results
provide
insights
into
how
disorder
soft‐yet‐resilient
enable
hopping,
particularly
3D
crystals.
Journal of Materials Chemistry A,
Год журнала:
2023,
Номер
11(44), С. 23999 - 24012
Опубликована: Янв. 1, 2023
The
local
structure
evolution
and
thermophysical
properties
of
the
NaCl–KCl–MgCl
2
–LaCl
3
melt
were
thoroughly
understood,
which
facilitates
advancement
innovation
molten
salt
electrolytic
production
for
Mg–La
alloys.
Journal of Materials Chemistry A,
Год журнала:
2024,
Номер
unknown
Опубликована: Янв. 1, 2024
Understanding
diffusion
mechanisms
in
solid
electrolytes
is
crucial
for
advancing
solid-state
battery
technologies.
This
study
investigates
the
role
of
structural
disorder
Li
