Advanced Science,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 17, 2024
The
rational
design
of
microwave
absorption
(MA)
material
featuring
light
weight,
wide
bandwidth,
and
infrared
stealth
property
is
crucial
for
military
health
protection
but
remains
challenging.
Herein,
an
innovative
N-doped
carbon
nanocage-in-microcage
structure
with
tunable
carbon-coated
Ni
(NC/Ni(HS))
reported
via
a
reliable
Ni-catalyzed
Ni-templated
method.
hierarchically
hollow
composites
can
optimize
the
impedance
matching
respond
to
multiple
reflections
scattering
incident
microwaves
waves.
Moreover,
magnetic
nanoparticles
improve
synergistic
interactions
between
confined
heterointerfaces
promote
interfacial
polarization.
Such
ingenious
endows
NC/Ni(HS)
outstanding
MA
performance
properties.
Specifically,
NC/Ni(HS)-10
optimal
dielectric
property,
exhibits
excellent
performance.
At
ultralow
fill
loading
4
wt.%,
bandwidth
6.16
GHz
achieved
at
thickness
2.63
mm,
strong
reflection
loss
-63.67
dB
obtained
2.00
mm.
In
addition,
shows
low
emissivity
in
range
3‒14
µm,
which
key
compatibility
stealth.
This
work
paves
way
advanced
materials
that
meet
requirements
multispectral-compatible
Advanced Functional Materials,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 7, 2024
Abstract
Multifunctionalization
of
electromagnetic
wave
absorbing
materials
(EMWAMs)
presents
a
promising
avenue
for
their
application
in
complex
scenarios.
However,
the
effective
integration
multiple
supplementary
functions
into
EMWAMs
continues
to
pose
significant
challenge.
Herein,
novel
nanofiber
elastomer
(NFE)
incorporating
multicomponent
inorganic
FeS
2
/S,N
co‐doped
carbon
nanofibers
(NFs)
and
organic
component
(Ecoflex)
are
designed
synthesized.
The
sulfur
doping
ratios
species
can
be
effectively
modulated
via
controlling
amount
sulfurization
temperature.
optimized
NFs/Ecoflex
NFE
not
only
exerted
an
excellent
impedance
matching
characteristic,
but
also
displays
boosted
conductive
loss
polarization
capacities.
Amongst,
achieved
ultra‐wide
absorption
bandwidth
(EAB)
7.40
GHz
minimum
reflection
(RL
min
)
−21.82
dB
at
thin
thickness
(≈2.00
mm).
Furthermore,
simultaneously
greatly
improved
mechanical
property,
thermal
insulation,
hydrophobicity,
corrosion
resistance.
Through
designing
metastructures,
with
periodically
closed‐ring
resonant
structure
realized
EAB
32.64
(ranging
from
7.36
40.00
GHz).
Overall,
this
research
contributes
valuable
insights
design
next‐generation
satisfactory
multifunctionalities,
demonstrating
potential
smart
devices
challenging
environments.
Journal of Advanced Ceramics,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 1, 2025
Ceramic
materials
have
obvious
advantages
in
thermal
stability,
but
impedance
mismatch
limited
their
ability
to
attenuate
electromagnetic
(EM)
waves.
Herein,
a
novel
series
of
high-entropy
(V0.2Nb0.2Zr0.2Ta0.2X0.2)B2
(X=Mo,
Ti,
Hf)
ceramics
were
successfully
and
rapidly
synthesized
using
the
ultrafast
high-temperature
sintering
(UHS)
method
based
on
joule
heating.
The
results
indicated
that
effect
component
control
magnetic
loss
system
was
relatively
small,
dielectric
larger.
Among
them,
HEB-Ti
sample
demonstrated
superior
absorbing
properties,
attributed
its
moderate
optimal
EM
matching.
At
same
time,
because
attenuation
constant,
it
can
achieve
maximum
penetration
wave
minimum
reflection
after
wave.
As
result,
(RLmin)
as
low
–40.7
dB,
effective
absorption
band
covered
entire
frequency
range
from
2
8
GHz.
Its
excellent
performance
mainly
due
synergistic
various
mechanisms,
including
defect
polarization,
dipole
conduction
loss.
Furthermore,
thermogravimetric
(TG)
analysis
showed
exhibited
stability
could
withstand
up
550
°C
air
1000
argon
gas
environment.
relevant
work
provided
meaningful
references
for
design
new
high-performance
ceramic
wave-absorbing
materials.
Small Methods,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Oct. 3, 2024
Abstract
Structural
design
and
interface
regulation
are
useful
strategies
for
achieving
strong
electromagnetic
wave
absorption
(EMWA)
broad
effective
bandwidth
(
EAB
).
Herein,
a
monomer‐mediated
strategy
is
employed
to
control
the
growth
of
covalent
organic
framework
(COF)
wrapping
flower‐shaped
Gd‐doped
FeNi
3
(GFN),
novel
raspberry‐like
absorbent
based
on
biomimetic
fabricated
by
thermal
catalysis.
Further,
unique
dielectric‐magnetic
synergistic
system
constructed
utilizing
COF‐derived
nitrogen‐doped
porous
carbon
(NPC)
as
shell
anisotropic
GFN
core.
The
parameters
GFN@NPC
composites
can
be
tuned
adjusting
proportions
NPC.
Off‐axis
electron
holography
results
further
clarify
polarization
microscale
magnetic
interactions
affecting
EMW
loss
mechanism.
As
result,
samples
exhibit
EMWA
performance.
values
all
reach
up
6.0
GHz,
with
GFN@NPC‐2
sample
showing
minimum
reflection
RL
min
)
−69.6
dB
at
1.68
mm.
In
addition,
achieves
maximum
radar
cross–section
(RCS)
reduction
29.75
dB·m
2
.
A
multi‐layer
gradient
structure
also
using
metamaterial
simulation
achieve
an
ultra‐wide
12.24
GHz.
Overall,
this
work
provides
bio‐inspired
develop
high‐performance
materials.
