With advancements in infrared detection technology, there is a need for fast, switchable camouflage. Here, we report an adaptive camouflage system that can be engineered to operate at any desired wavelength the technologically relevant, transparent 3–5 and 8–12 μm bands. Adaptive actuated by exploiting semiconductor metal phase transition VO2, which modifies reflection spectra of multilayered cavity-coupled plasmonic system. The temperature-dependent permittivity VO2 calculated using...

We report a novel synthesis approach for the growth of core/shell FeO/Fe3O4 nanoparticles with controlled shape and size. FeO particles were partially oxidized to form structures, as evidenced from transmission electron microscopy, X-ray diffraction, magnetometry analysis. find that molar ratios concentrations surfactants are key parameters in controlling particle The can grow either isotropic or anisotropic shapes, depending upon chemical reaction scheme is kinetically thermodynamically....

We demonstrate the possibility of enhancing both magnetocaloric effect (MCE) and refrigerant capacity (RC) in nanostructured mixed phase manganites. A comparative study magnetic properties La0.35Pr0.275Ca0.375MnO3 single crystalline nanocrystalline forms is presented. While conventional trend reduction magnetization MCE with nanostructuring, we show that opposite true case The charge-ordered state largely suppressed ferromagnetic order established sample an average particle size 50 nm....

A detailed study is presented on Fe/\ensuremath{\gamma}-Fe${}_{2}$O${}_{3}$ core-shell structured nanoparticles (mean size \ensuremath{\sim}10 nm) to understand the spin dynamics of core and shell independently their role in triggering exchange bias (EB) phenomena. The particle critically slow down at ${T}_{g}$ \ensuremath{\sim} 68 K, below which they exhibit memory effect field-cooled zero-field-cooled protocols associated with a superspin glass state. field dependence mean blocking...

A comprehensive study of the temperature ($T$) and magnetic field ($H$) dependence entropy change ($\ensuremath{\Delta}{S}_{M}$) for different materials exhibiting inverse magnetocaloric effect (IMCE) is reported. We show that $\ensuremath{\Delta}{S}_{M}$ follows a power-law $H$ ($\ensuremath{\Delta}{S}_{M}$ \ensuremath{\sim} ${H}^{n}$; $n$ an exponent) these compounds. In contrast to conventional (CMCE), independent $T$ in case IMCE. As result, universal master curve can be constructed...

Enhancing light-matter interaction by exciting Dirac plasmons on nanopatterned monolayer graphene is an efficient route to achieve high infrared absorption. Here, we designed and fabricated hexagonal planar arrays of nanoholes nanodisks with without optical cavity excite patterned investigate the role plasmon lifetime, extinction cross-section, incident light polarization, angle light, pattern dimensions light-absorption spectra. By incorporating a high-k Al2O3 layer as gate dielectric for...

Abstract Due to the low photon energy, detection of infrared photons is challenging at room temperature. Thermoelectric effect offers an alternative mechanism bypassing material bandgap restriction. In this article, we demonstrate asymmetric plasmon-induced hot-carrier Seebeck photodetection scheme temperature that exhibits a remarkable responsivity 2900 VW −1 , detectivity 1.1 × 10 9 Jones along with fast response ~100 ns in technologically relevant 8–12 µm band. This achieved by...

We report the synthesis and magnetic properties of core/shell FeO/Fe3O4 nanoparticles with an average size 30 nm in a complex quasi-octopod shape. FeO were synthesized by wet chemical route followed partial oxidation to form structured octopods. X-ray diffraction transmission electron microscopy confirmed presence iron oxide phases formed morphology. Magnetic measurements revealed two distinct temperatures corresponding thermally activated Verwey transition (TV ∼ 120 K) ferrimagnetic Fe3O4...

The high carrier mobility of graphene makes it an attractive material for electronics, however, graphene's application optoelectronic systems is limited due to its low optical absorption. We present a cavity-coupled nanopatterned absorber designed sustain temporal and spatial overlap between localized surface plasmon resonance cavity modes, thereby resulting in enhanced absorption up unprecedented value theoretically $(60%)$ experimentally measured $(45%)$ monolayer the technologically...

We report a detailed investigation of the magnetocaloric properties self-doped polycrystalline LaMnO(3+δ) with δ = 0.04. Due to self-doping effect, system exhibits magnetic transition from paramagnetic ferromagnetic-like canted state (CMS) at ~120 K, which is associated an appreciably large effect (MCE). The CMS inhomogeneous phase developing due steady growth antiferromagnetic correlation in its predominant ferromagnetic below ∼120 K. stabilization this material concluded comprehensive...

We report the universal behavior of inverse magnetocaloric effect (IMCE) in antiferromagnetic materials. In contrast to conventional often observed ferromagnetic systems, a phenomenological master curve can be constructed describe temperature dependence magnetic entropy change for IMCE without rescaling axis. The proposed method allows extrapolating an material, which would imperative judge its suitability actual refrigeration devices.

The origin of asymmetry in field cooled (FC) hysteresis loops exhibiting exchange bias (EB) is investigated by studying the static and dynamic magnetic properties core-shell Co/CoO nanoparticles. Two distinct freezing temperatures coresponding to core (Tf-cr ∼ 190 K) shell moments (Tf-sh 95 are obtained from energy barrier distribution. FC symmetric temperature range Tf-sh ≤ T Tf-cr, however, observed immediately below Tf-sh. These intriguing features also probed radio frequency transverse...

We report exchange bias (EB) effect in the Au-Fe3O4 composite nanoparticle system, where one or more Fe3O4 nanoparticles are attached to an Au seed particle forming dimer and cluster morphologies, with clusters showing much stronger EB comparison dimers. The develops due presence of stress interface which leads generation highly disordered, anisotropic surface spins particle. is lost removal interfacial stress. Our atomistic Monte-Carlo studies excellent agreement experimental results. These...

A two-step magnetically assisted capillary action method is demonstrated as a facile technique to produce hollow carbon nanotubes filled with uniformly dispersed Fe3O4 nanoparticles (NPs). Template-assisted chemical vapor deposition (CVD) grown CNTs average diameter 200–300 nm and length 5–6 µm were effectively used 'nanostraws' suck in chemically synthesized (mean size ∼6 nm) ferrofluid suspension. Temperature magnetic field-dependent DC magnetization measurements indicate that these...

Nanostructured magnetic materials with well-defined anisotropy are very promising as building blocks in spintronic devices that operate at room temperature. Here we demonstrate the epitaxial growth of highly oriented Fe3O4 nanorods on a SrTiO3 substrate by hydrothermal synthesis without use seed layer. The showed biaxial an order magnitude difference between field values easy and hard axes. Using combination conventional magnetometry, transverse susceptibility, force microscopy (MFM)...

We report here the growth and characterization of functional oxide nanowire hole doped manganite La 0.5 Sr MnO 3 (LSMO). also four‐probe electrical resistance measurement a single LSMO (diameter ~45 nm) using focused ion beam (FIB) fabricated electrodes. The wires are by hydrothermal method autoclave at temperature 270 °C. elemental analysis physical property like resistivity studied an individual level. quantitative determination Mn valency mapping constituent elements done Electron Energy...

We report on the phase coexistence and magnetic anisotropy in polycrystalline (bulk) nanocrystalline (∼15 nm) LaMnO3+δ materials, which were prepared by solid state reaction sol-gel methods, respectively. In addition to standard magnetization measurements, radio-frequency transverse susceptibility (TS) based a very sensitive, self-resonant tunnel diode oscillator method was used probe switching fields samples. The results revealed of ferromagnetic (FM) antiferromagnetic (AFM) phases both For...

We report the first observation of inverse magnetocaloric effect (IMCE) in hydrothermally synthesized single crystalline La0.5Sr0.5MnO3 nanowires. The core nanowires is phase separated with development double exchange driven ferromagnetism (FM) antiferromagnetic (AFM) matrix, whereas surface found to be composed disordered magnetic spins. FM scales effective anisotropy, which directly probed by transverse susceptibility experiments. exhibits a glassy behavior and undergoes spin freezing,...

The development of positive magnetic entropy change in the case ferromagnetic (FM) nanostructures is a rare occurrence. We observe core/shell (Fe/γ-Fe2O3) and hollow (γ-Fe2O3) nanoparticles its origin attributed to disordered state due random distribution anisotropy axes which inhibits any long range FM ordering. effect energy barrier on impact universal behavior based rescaled curves for discussed. Our study emphasizes that an excellent parameter temperature field dependent freezing such...

We observe an enhanced magnetic entropy change (−ΔSM) at cryogenic temperatures (T < 20 K) in Eu8Ga16Ge30 clathrate (type-I) nanocrystals prepared by a ball milling method. With reduction the crystal size to 15 nm, −ΔSM is low temperatures, reaching highest value (∼10 J/kg 5 K for field of T. For all samples investigated, there cross-over temperature (∼25 (T) above which decreases with size, opposite that observed temperatures. A careful analysis and magnetocaloric data reveals as...