Nanodomain Structure Research Articles

Designing a novel low-density, high-strength Al12Nb25.5Ta8.5Ti27.5Zr26.5 refractory high-entropy alloy for medium-temperature applications

This study introduces a novel Al12Nb25.5Ta8.5Ti27.5Zr26.5 Refractory High-Entropy Alloy (RHEA), designed for medium-temperature structural applications while addressing the density problem and strength-ductility trade-off in RHEAs. The alloy was synthesized using vacuum arc melting (VAC) and characterized through comprehensive experimental methods including X-ray diffraction (XRD), scanning electron microscopy (SEM) with attached energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). This RHEA demonstrated exceptional mechanical properties, achieving a yield strength of 1301 MPa and a specific yield strength of 188.5 MPa·g−1·cm3 at room temperature, with notable ductility (compressive strain >69 %) across a wide temperature range up to 1000 °C.The microstructural analysis revealed a two-phase BCC/B2 nanodomain structure that contributes significantly to its strength and ductility from 20 °C to 600 °C.

Anesthetic Mechanisms: Synergistic Interactions With Lipid Rafts and Voltage-Gated Sodium Channels.

Despite successfully utilizing anesthetics for over 150 years, the mechanism of action remains relatively unknown. Recent studies have shown promising results, but due to the complex interactions between anesthetics and their targets, there remains a clear need for further mechanistic research. We know that lipophilicity is directly connected to anesthetic potency since lipid solubility relates to anesthetic partition into the membrane. However, clinically relevant concentrations of anesthetics do not significantly affect lipid bilayers but continue to influence various molecular targets. Lipid rafts are derived from liquid-ordered phases of the plasma membrane that contain increased concentrations of cholesterol and sphingomyelin and act as staging platforms for membrane proteins, including ion channels. Although anesthetics do not perturb membranes at clinically relevant concentrations, they have recently been shown to target lipid rafts. In this review, we summarize current research on how different types of anesthetics-local, inhalational, and intravenous-bind and affect both lipid rafts and voltage-gated sodium channels, one of their major targets, and how those effects synergize to cause anesthesia and analgesia. Local anesthetics block voltage-gated sodium channel pores while also disrupting lipid packing in ordered membranes. Inhalational anesthetics bind to the channel pore and the voltage-sensing domain while causing an increase in the number, size, and diameter of lipid rafts. Intravenous anesthetics bind to the channel primarily at the voltage-sensing domain and the selectivity filter, while causing lipid raft perturbation. These changes in lipid nanodomain structure possibly give proteins access to substrates that have translocated as a result of these structural alterations, resulting in lipid-driven anesthesia. Overall, anesthetics can impact channel activity either through direct interaction with the channel, indirectly through the lipid raft, or both. Together, these result in decreased sodium ion flux into the cell, disrupting action potentials and producing anesthetic effects. However, more research is needed to elucidate the indirect mechanisms associated with channel disruption through the lipid raft, as not much is known about anionic lipid products and their influence over voltage-gated sodium channels. Anesthetics' effect on S-palmitoylation, a promising mechanism for direct and indirect influence over voltage-gated sodium channels, is another auspicious avenue of research. Understanding the mechanisms of different types of anesthetics will allow anesthesiologists greater flexibility and more specificity when treating patients.

Complementary nanodomain structures in topologically close-packed precipitates of Al-Zn-Mg-Cu alloy

High-strength aluminium alloys attract continuous research interest, owing to their wide use in aerospace and terrestrial transportation industries. The performance of the alloys is essentially determined by nanoscale precipitates, thus understanding the structure and formation mechanism of the precipitates during thermal processing is of great importance. Here, we reveal complementary domain structures in precipitates in a high-strength Al-Zn-Mg-Cu alloy using a combination of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Through the transfer of fivefold symmetry polyhedra at domain boundaries, the intermediate precipitates develop two sets of highly ordered and structurally complementary nanoscale domains in their nucleation and growth. This new type of atom packing maintains the topologically close-packed structure inside the precipitates while reducing the lattice misfit with the Al matrix and the barrier of structural transformations on two interfaces, demonstrating good thermal stability. Our discoveries lead to insight into the precipitate evolution in the Al-Zn-Mg-Cu alloy system and can help understand other precipitation processes of complex structured phases. Furthermore, the evolution process demonstrates an advanced mode of building metastable architectures with nanoscale interlocking pieces in alloy matrixes, which may inspire strategies to obtain high-strength, lightweight and thermostable alloys.

Formation of self-assembled nanodomain structure as a result of motion of oriented planar phase boundary in single crystals of tetragonal PMN-PT

We studied the formation of the domain structure as a result of the motion of a planar interphase boundary in the {001}-cut tetragonal PMN-PT crystals during cooling with oriented temperature gradient. The specialized heating/cooling stage was assembled for this purpose. Piezoresponse force microscopy was used to image the domain structure at the (001) and (010) surfaces of the samples with high spatial resolution, revealing a complex quasi-periodic domain pattern with a periodicity from 300 to 400 nm.

The effect of heat treatment on microstructure and martensitic transformation temperatures in Ni44Fe19Ga27Co10 single crystals

Abstract The microstructure and temperature of martensitic transformation of Ni44Fe19Ga27Co10 single crystals after aging at temperatures from 623 K to 1173 K were studied by electron microscopy and differential scanning calorimetry. The temperature ranges of the second phase precipitation, their lattice structure and volume fraction, and also the modification of the nanodomain structure of the L21+B2 high-temperature phase were determined in dependence on aging temperature. The influence of microstructure parameters on the martensitic transformation temperatures, transformation intervals and thermal hysteresis has been discussed.

Functional Hydrogels Based on Design of Nanodomain Structure

Functional Hydrogels Based on Design of Nanodomain Structure

Phase separation in model lipid membranes investigated with cryogenic electron microscopy.

We describe a method for investigating lateral membrane heterogeneity using cryogenic electron microscopy (cryo-EM) images of liposomes. The method takes advantage of differences in the thickness and molecular density of ordered and disordered phases that are resolvable in phase contrast cryo-EM. Compared to biophysical techniques like FRET or neutron scattering that yield ensemble-averaged information, cryo-EM provides direct visualization of individual vesicles and can therefore reveal variability that would otherwise be obscured by averaging. Moreover, because the contrast mechanism involves inherent properties of the lipid phases themselves, no extrinsic probes are required. We explain and discuss various complementary analyses of spatially resolved thickness and intensity measurements that enable an assessment of the membrane's phase state. The method opens a window to nanodomain structure in synthetic and biological membranes that should lead to an improved understanding of lipid raft phenomena.

Evaluating fracture properties and interfacial strengths of silicon oxycarbide thin-films: XFEM simulations and experimental validation

Silicon oxycarbide (SiCO) thin films with unique nano-domain structure show various functional properties and high-temperature stability, and the mechanical property at the interface between SiCO and substrate is one of the critical issues for enhancing reliabilities of microelectronic thin-film devices. In this work, the fracture properties and interfacial strengths of SiCO thin films are investigated by experiments and extended finite element (XFEM) method. The elastic and plastic properties of the SiCO/substrate interfaces are obtained by fitting the XFEM calculated P-h curves with those from nano-indentation experiments, fracture toughnesses and energy release rates are obtained to improve the description of interfacial crack nucleation and propagation. Then the properties are used as the inputting parameters of XFEM model for scratch simulations, and the critical loads for evaluating interfacial strength are achieved. The calculated critical loads are comparable to the results of experimental scratch, and the influences of layer thickness on interfacial strength of SiCO thin-film are nicely predicted.

Co-regulation of phase-domain structure in Bi0.5Na0.5TiO3- based ferroelectrics to optimize energy storage properties

Sodium bismuth titanate (BNT)-based dielectric capacitors with excellent energy storage performance play an important role in electronics industry. (Sr1.05Bi0.3)ScO3 (SBS) is introduced into 0.85Bi0.5Na0.5TiO3-0.15NaNbO3 (BNT-NN) to achieve co-regulation of phase and domain structure. With the introduction of SBS, the dominated pseudocubic phase accompanied by a small percentage of rhombohedral phase are tend to form, and thus induce nanodomain structure with high-density domain walls. Under the excitation of a bias voltage, the induced nanodomains are easier to switch and effectively reduce the residual polarization. Additionally, the homogeneous nanodomains with high-density domain walls will promote large negative built-in voltage which are favorable to rise of breakdown field strength, and thus, optimize the energy storage performance. The co-regulation of phase-domain structure provides an idea for designing ferroelectrics with good energy storage performance.

Laser nanoprinting of 3D nonlinear holograms beyond 25000 pixels-per-inch for inter-wavelength-band information processing

Nonlinear optics provides a means to bridge between different electromagnetic frequencies, enabling communication between visible, infrared, and terahertz bands through χ(2) and higher-order nonlinear optical processes. However, precisely modulating nonlinear optical waves in 3D space remains a significant challenge, severely limiting the ability to directly manipulate optical information across different wavelength bands. Here, we propose and experimentally demonstrate a three-dimensional (3D) χ(2)-super-pixel hologram with nanometer resolution in lithium niobate crystals, capable of performing advanced processing tasks. In our design, each pixel consists of properly arranged nanodomain structures capable of completely and dynamically manipulating the complex-amplitude of nonlinear waves. Fabricated by femtosecond laser writing, the nonlinear hologram features a pixel diameter of 500 nm and a pixel density of approximately 25000 pixels-per-inch (PPI), reaching far beyond the state of the art. In our experiments, we successfully demonstrate the novel functions of the hologram to process near-infrared (NIR) information at visible wavelengths, including dynamic 3D nonlinear holographic imaging and frequency-up-converted image recognition. Our scheme provides a promising nano-optic platform for high-capacity optical storage and multi-functional information processing across different wavelength ranges.

Nanomicellar Electrolyte To Control Release Ions and Reconstruct Hydrogen Bonding Network for Ultrastable High-Energy-Density Zn-Mn Battery.

Zn-Mn batteries with two-electron conversion reactions simultaneously on the cathode and anode harvest a high voltage plateau and high energy density. However, the zinc anode faces dendrite growth and parasitic side reactions while the Mn2+/MnO2 reaction on the cathode involves oxygen evolution and possesses poor reversibility. Herein, a novel nanomicellar electrolyte using methylurea (Mu) has been developed that can encapsulate ions in the nanodomain structure to guide the homogeneous deposition of Zn2+/Mn2+ in the form of controlled release under an external electric field. Consecutive hydrogen bonding network is broken and a favorable local hydrogen bonding system is established, thus inhibiting the water-splitting-derived side reactions. Concomitantly, the solid-electrolyte interface protective layer is in situ generated on the Zn anode, further circumventing the corrosion issue resulting from the penetration of water molecules. The reversibility of the Mn2+/MnO2 conversion reaction is also significantly enhanced by regulating interfacial wettability and improving nucleation kinetics. Accordingly, the modified electrolyte endows the symmetric Zn∥Zn cell with extended cyclic stability of 800 h with suppressed dendrites growth at an areal capacity of 1 mAh cm-2. The assembled Zn-Mn electrolytic battery also demonstrates an exceptional capacity retention of nearly 100% after 800 cycles and a superior energy density of 800 Wh kg-1 at an areal capacity of 0.5 mAh cm-2.

La-doped PMN–PT transparent ceramics with ultra-high electro-optic effect and its application in optical devices

Transparent electro-optic (EO) ceramics of La-doped 0.75Pb(Mg_1/3Nb_2/3)O₃–0.25PbTiO₃ (0.75PMN–0.25PT) were prepared successfully. High transparency of 69% in the near-infrared (IR) wavelength (1550 nm) was achieved at 2 mol% La doping, meanwhile it shows an extremely high quadratic EO coefficient of 45.4×10⁻¹⁶ m²·V⁻², which is indispensable for applications in EO devices. The distribution of a polar nanodomain structure of the samples experiences disorder–order–disorder evolution in a La doping range. It is found that a parallelly-stacked polar nanodomain structure with an easier and faster polarization switching in the 2 mol% La-doped sample suggests that an ordering distribution of polar nanoregions would be critical to inducing large EO effect, transparency, and piezoelectric response. A triple-cavity tunable optical filter (TOF) with a single transmission peak and a tuning voltage below 30 V in a tuning range of 190–197 THz was designed based on our ceramics. The work is believed to bridge the relationship among doping-engineering, EO properties, and polarization behavior, which would guide the further optimization of transparent EO ceramics.

Highly mismatched antiferroelectric films: Transition order and mechanical state

Epitaxial ${\mathrm{PbZrO}}_{3}/{\mathrm{SrRuO}}_{3}/{\mathrm{SrTiO}}_{3}$ heterostructures are among the most widely studied thin-film antiferroelectrics. This paper explores their temperature-induced phase transitions and the characteristics of the domain structure by means of high-resolution synchrotron x-ray diffraction. The antiferroelectric transition order appears to change from the first to the second; peculiar in-plane $M$-point superstructures develop at high temperatures, manifesting a new phase; the $R$- and $\mathrm{\ensuremath{\Sigma}}$-point superstructure reflections demonstrate much reduced splitting as compared to the demands of the mechanical compatibility. We discuss the energetics of the reduced around-the-normal antiferroelectric domain tilts, its relation to the observed changes in phase transitions, and point to the possible contribution to the observed effect from an unusual diffraction mechanism related to the partial coherence between domains in a random nanodomain structure.

Melt blending crystallization regulating balanced nanodomains in efficient and scalable coating processed organic solar cells

The miscibility between active layer donors (D) and acceptors (A) is a key factor impeding the development of organic photovoltaics (OPVs) toward higher performance and large-area production. In this study, melt blending crystallization (MBC) was used to accomplish molecular-level blending and highly oriented crystallization in bulk heterojunction (BHJ) films realized by a scalable blade coating process, which increased the D/A contact area and provided sufficient exciton diffusion and dissociation. At the same time, the highly organized and balanced crystalline nanodomain structures permitted dissociated carriers to be efficiently transmitted and collected, resulting in significantly enhanced short-circuit current density, fill factor, and efficiency of the device by means of optimum melting temperature and quenching rates. The method can be simply incorporated into current efficient OPV material systems and achieve a device performance comparable to the best values. The blade-coating-processed PM6/IT-4F MBC devices achieved an efficiency of 13.86% in a small-area device and 11.48% in a large-area device. A power conversion efficiency (PCE) of 17.17% was obtained in PM6:BTP-BO-4F devices, and a PCE of 16.14% was acquired in PM6:Y6 devices.

Mechanically Driven Reversible Polarization Switching in Imprinted BiFeO3 Thin Films

AbstractMechanically driven polarization switching via scanning probe microscopy provides a valuable voltage‐free strategy for designing ferroelectric nanodomain structures. However, it is still challenging to realize reversible polarization switching with mechanical forces. Here, the mechanically driven reversible polarization switching observed in imprinted ferroelectric BiFeO3 thin films is reported, i.e., up‐to‐down switching by a sharp scanning tip and down‐to‐up switching by a blunt tip. Free energy calculations, phase‐field simulations, and piezoresponse force microscopy reveal that reversible mechanical switching arises from the interplay among the flexoelectric effect, the piezoelectric effect, and the internal upward built‐in field in BiFeO3 films. This study gains a deeper insight into the mechanism and control of mechanically driven polarization switching, and provides guidance for exploring potential ferroelectric‐based electro‐mechanical microelectronics.

Excellent thermal stability and high energy storage performances of BNT-based ceramics via phase-structure engineering

Herein, a novel strategy for regulating the phase structure was used to significantly enhance the recoverable energy storage density (Wrec) and the thermal stability via designing the (1-x)[(Bi0.5Na0.5)0.7Sr0.3TiO3]-xBiScO3 ((1-x)BNST-xBS) relaxor ferroelectric ceramics. The incorporation of BS into BNST ceramics markedly increases the local micro-structure disorder, causing a high polarization and inhibiting polarization hysteresis for 0.95BNST-0.05BS ceramics, leading to a large Wrec of 5.41 J/cm3 with an ideal efficiency (η) of 78.5%. Meanwhile, transmission electron microscope (TEM) results further proved that the nano-domain structure and the tetragonal (P4bm) phase superlattice structure of 0.95BNST-0.05BS ceramics possess an excellent thermal stability (20–200 °C). An outstanding Wrec value of 3.18 × (1.00 ± 0.03) J/cm3 and an η value of 74.500 ± 0.025 are achieved under a temperature range from 20 °C to 200 °C. This work provides a promising method for phase-structure design that can make it possible to apply temperature-insensitive ceramic dielectrics with a high energy storage density in harsh environments.

Enhancing Energy Storage Performance in Lead-Free Bismuth Sodium Niobate-Based Tungsten Bronze Ceramics through Relaxor Tuning.

A series of tungsten bronze Sr2Na0.85Bi0.05Nb5-xTaxO15 (SBNN-xTa) ferroelectric ceramics were designed and synthesized by the traditional solid-phase reaction method. The B-site engineering strategy was utilized to induce structural distortion, order-disorder distribution, and polarization modulation to enhance relaxor behavior. Through investigating the impact of B-site Ta replacement on the structure, relaxor behavior, and energy storage performance, this study has shed light on the two main factors for relaxor nature: (1) with the increase of Ta substitution, the tungsten bronze crystal distortion and expansion induced the structural change from an orthorhombic Im2a phase to Bbm2 phase at room temperature; (2) the transition from ferroelectric to relaxor behavior could be attributed to the coordinate incommensurate local superstructural modulations and the generation of nanodomain structure regions. Moreover, we benefited from the effective decrease of ceramic grains and inhibition of abnormal growth. Finally, we obtained an effective energy storage density (Wrec) ∼ 1.6 J/cm3, an efficiency (η) ∼ 80%, a current density (CD) ∼ 1384.2 A/cm2, and a power density (PD) ∼ 138.4 MW/cm3.

Regional consistency between cation displacement and oxygen octahedral tilt in nanodomain of BNKT-SBT relaxor ferroelectrics revealed by atomic-resolution AC-STEM

Since being discovered, relaxor ferroelectrics have attracted continued interest due to their unusual properties. Relaxor behavior is attributed to nanodomains or PNRs. Therefore, nano-scale even atomic-scale structural analysis is crucial to understanding the relaxor properties. However, the atomic-scale nanodomain structure has not been fully understood. For Bi0.5Na0.5TiO3, cation displacement and oxygen octahedral tilt are two common structural distortions. However, the relationship between them has not been proved experimentally. Here, the cation displacement and octahedral tilt were both investigated based on aberration-corrected STEM images. Cation displacement vectors illustrate a vortex structure. Octahedral tilt is regionally consistent with cation displacement that both of them increase gradually from the domain wall to the interior of the nanodomain. The formation of nanodomains may originate from their combined effect, thereby producing relaxor properties. Moreover, oxygen octahedral displacement stemmed from the complex coordinating environments was observed. These findings provide further insights into the nanodomain structure.

STRUCTURE, MARTENSITIC TRANSFORMATIONS AND MECHANICAL PROPERTIES OF AGING NANOCRYSTALLINE TI-50.9 AT % NI ALLOY

The effect of aging temperature in the range of 300-500°C on the structure, R martensitic transformations and mechanical characteristics of nanocrystalline Ti-50.9 at % Ni alloy with a grain/subgrain structure was studied. It was found that variation in the spatial distribution of coherent Ti3Ni4 particles in the nanostructure from their location on dislocations during low-temperature aging to precipitation at dislocation boundaries under intense aging is accompanied by a change in the morphology of the R phase from a nanodomain to a self-accommodating lamellar structure. The nanodomain structure of the R phase contributes to uniform deformation of the alloy during loading/unloading and stabilization of superelasticity. When loading the alloy with a lamellar R-phase morphology, localized deformation bands are formed by the R-phase reorientation in a Luders deformation manner.

Strong spin-lattice entanglement in cobaltites

Strongly correlated electronic system contains strong coupling among multi-order parameters and is easy to efficiently tune by external field. Cobaltite (LaCoO<sub>3</sub>) is a typical multiferroic (ferroelastic and ferromagnetic) material, which has been extensively investigated over decades. Conventional research on cobaltites has focused on the ferroelastic phase transition and structure modulation under stress. Recently, researchers have discovered that cobaltite thin films undergo a paramagnetic-to-ferromagnetic phase transition under tensile strain, however, its origin has been controversial over decades. Some experimental evidence shows that stress leads the valence state of cobalt ions to decrease, and thus producing spin state transition. Other researchers believe that the stress-induced nano-domain structure will present a long-range ordered arrangement of high spin states, which is the main reason for producing the ferromagnetism of cobalt oxide films. In this paper, we review a series of recent researches of the strong correlation between spin and lattice degrees of freedom in cobalt oxide thin films and heterojunctions. The reversible spin state transition in cobalt oxide film is induced by structural factors such as thin-film thickness, lattice mismatch stress, crystal symmetry, surface morphology, interfacial oxygen ion coordination, and oxygen octahedral tilting while the valence state of cobalt ions is kept unchanged, and thus forming highly adjustable macroscopic magnetism. Furthermore, the atomic-level precision controllable film growth technology is utilized to construct single cell layer cobaltite superlattices, thereby achieving ultra-thin two-dimensional magnetic oxide materials through efficient structure regulation. These advances not only clarified the strong coupling between lattice and spin order parameters in the strongly correlated electronic system, but also provided excellent candidate for the realization of ultra-thin room temperature ferromagnets that are required by oxide spintronic devices.