Preferential Growth Research Articles

Synthesis and Characterization of Nano-Crystallite Triple Super Phosphate (TSP) from Marine Mollusk Waste: Babylonia japonica, Oliva sayana, and Conasprella bermudensis.

The study aims to synthesize nano-crystallite TSP using renewable, low-cost, waste marine mollusk from three different species such as Babylonia japonica, Oliva sayana, and Conasprella bermudensis. The molar ratio of phosphate to calcium in triple superphosphate [TSP, Ca(H2PO4)2.H2O] significantly impacts its properties and fertilizer performance, in this case, we kept the ratio to 2. Raw TSP has a high phosphate content and lower calcium content. The synthesized TSP was analyzed using various techniques including TGA, XRD, EDX, FT-IR, and SEM. The study utilized multiple XRD model equations to analyze crystallite size ( ), with all models except the Liner straight-line method providing higher estimates for synthesized TSP. Furthermore, the values for stress (2×107 to 4×107 N/m2), strain (4×10-4 to 9×10-4), as well as energy density (4.54×103 to 16.27×103 J/m3) were also calculated for the synthesized product. However, the preferential growth calculation indicates that (010), (021), and (020) planes are the most thermodynamically stable planes for the growth of the synthesized TSP. Apart from that, FTIR result confirms that CaO, -OH, as well as PO4 3- functional groups are present in the synthesized products. This research suggests that marine mollusks can be utilized as a calcium precursor for P-fertilizer and 60 % phosphoric acid, thereby reducing production costs by eliminating additional dehydrating. Additionally, waste marine mollusk shells could be utilized as an alternative to the production of phosphate-based fertilizer.

Shape Anisotropy of Grains Formed by Laser Melting of (CoCuFeZr)17Sm2

For permanent magnetic materials, anisotropic microstructures are crucial for maximizing remanence Jr and maximum energy product (BH)max. This also applies to additive manufacturing processes such as laser powder bed fusion (PBF-LB). In PBF-LB processing, the solidification behavior is determined by the crystal structure of the material, the substrate, and the melt-pool morphology, resulting from the laser power PL and scanning speed vs. To study the impact of these parameters on the textured growth of grains in the melt-pool, experiments were conducted using single laser tracks on (CoCuFeZr)17Sm2 sintered magnets. A method was developed to quantify this grain shape anisotropy from electron backscatter diffraction (EBSD) analysis. For all grains in the melt-pool, the grain shape aspect ratio (GSAR) is calculated to distinguish columnar (GSAR < 0.5) and equiaxed (GSAR > 0.5) grains. For columnar grains, the grain shape orientation (GSO) is determined. The GSO represents the preferred growth direction of each grain. This method can also be used to reconstruct the temperature gradients present during solidification in the melt-pool. A dependence of the melt-pool aspect ratio (depth/width) on energy input was observed, where increasing energy input (increasing PL, decreasing vs) led to higher aspect ratios. For aspect ratios around 0.3, an optimum for directional columnar growth (93% area fraction) with predominantly vertical growth direction (mean angular deviation of 23.1° from vertical) was observed. The resulting crystallographic orientation is beyond the scope of this publication and will be investigated in future work.

The Impact of Bromine Surface Doping on the Structural, Optical, and Morphological Properties of Bismuth‐Based Perovskite Film as a Light‐Absorber in Perovskite Solar Cells

Bismuth‐based perovskite materials have concerned significant attention due to their low‐toxic and stable properties. However, achieving smooth and dense thin films for the preferential growth of bismuth‐based perovskite along the c‐axis, which is conducive to the preparation of solar cells, is challenging. Therefore, using halogen atoms to partially replace iodine atoms and constrain anisotropic growth has been shown to be an effective method for obtaining high‐quality perovskite films. Herein, Br doping with varying concentrations is used to treat bismuth‐based perovskite films with larger and denser grains compared to those without doping. When a small amount of Br ions is doped, the surface of the perovskite layer becomes more uniform, significantly improving the compactness of the perovskite film. Additionally, proper Br doping can reduce internal defects in the films, effectively inhibiting nonradiative recombination, enhancing light absorption, and increasing carrier lifetime. The optimal power conversion efficiency of Br‐doped bismuth halide perovskite solar cells is found to be 0.136%, compared to 0.087% for pristine devices.

Understanding the Role of Solvent on the Growth of Zinc Oxide: Insight from Experiment and Molecular Dynamics Simulations.

The controlled synthesis of nanoparticles with tailored shapes and morphologies has garnered significant attention, driven by the ever-growing demand for advanced materials with defined properties. In nanoparticle formation, various parameters influence the final product, and among these, the solvent plays a pivotal role, as it constitutes the major component of the reaction medium. In this work, the critical role of solvents in controlling the growth of zinc oxide (ZnO) nanoparticles was investigated, with a focus on simple primary alcoholic solvents as the reaction medium. A model reaction based on the direct solvolysis of anhydrous zinc acetylacetonate was employed to probe the influence of different primary alcohols, specifically methanol, ethanol, and their mixture. A substantial difference in the preferential growth direction of the ZnO nanocrystals in methanol and ethanol was observed through XRD and was further proven through TEM. Thereby, in ethanol, a preferential growth in the [001] direction was observed, resulting in short nanorods as primary particles, while this growth was inhibited in methanol, leading to platelet- or sheet-like primary particles. To unravel the underlying mechanisms responsible for the observed solvent-dependent variations, molecular dynamics (MD) simulations were employed using an optimized interface force field to model the ZnO-alcohol interaction. These simulations provide valuable insights into the preferential adsorption of the solvent molecules onto the polar (0001) and (0001̅) and nonpolar (101̅0) ZnO surfaces, shedding light on the fundamental interactions driving the shape control phenomenon. Essentially, the experimental observations on primary particle morphology could be explained well by the adsorption behavior determined by the MD simulations. Furthermore, this report provides an extensive comparison with various similar reaction systems for ZnO synthesis, deriving correlations with the findings from the model system. These insights contribute to a deeper understanding of the intricate interplay between solvent properties and nanoparticle growth, offering a valuable toolkit for designing and optimizing the synthesis of ZnO nanoparticles with specific shapes and functionalities.

Polyoxometalate Initiated In situ Conformal Coating of Multifunctional Hybrid Artificial Layers for High Performance Zinc Metal Anodes

AbstractAqueous zinc (Zn) metal batteries are very attractive owing to the high theoretical capacity (820 mAh g−1), meritable electrode potential (−0.76 V vs SHE), low cost, and environmental friendliness of Zn metal anodes. However, the dendrite formation, corrosion, and water decomposition on Zn metal anodes should be resolved for their practical applications. Herein, conformally coated multifunctional organic/inorganic hybrid artificial layers are demonstrated for the reversible and stable Zn deposition. These hybrid layers are synthesized through polyoxometalate (POM) initiated polymerization into poly(1,3‐dioxolane) (Poly(DOL)) and directly coated onto the Zn surface. Moreover, POM acted as chemical bridge connecting Poly(DOL) with Zn metal anode to construct mechanically robust layers with a thickness of ≈40 nm. The fast and selective Zn2+ ion transport of multifunctional POM/Poly(DOL) hybrid layer (POMDOL) and their preferential growth into (002) crystalline plane are attributed to the reversible Zn deposition. Accordingly, POMDOL coated Zn (PDOLZn) anodes achieves an extended cycling period up to 2,876 hours with a cumulative capacity of 29 Ah g−1 at 20 mA cm−2 and 1 mAh cm−2. Moreover, depth of discharge (DOD) of 40% is achieved. Consequently, the PDOLZn || β‐MnO2 full cells delivered the high specific capacity of 245 mAh g−1 and long‐term stability over 1 000 cycles.

Growth orientation control in rapid solid-state crystal growth of (K,Na)NbO3 single crystals using plate-like NaNbO3 single crystal particles

The rolling-extended orientation technique and plate-like NaNbO3 (NN) single crystal particles prepared by a single-step molten salt synthesis, both of which have been developed to fabricate (K, Na)NbO3 (KNN) textured ceramics, were utilized to control the growth orientation of KNN single crystals synthesized by a rapid solid-stated crystal growth (RSSCG) method. As the seed crystals, two kinds of NN single crystal particles were synthesized using pure NaCl and KCl-NaCl mixed molten salts. Plate-like KNN single crystals of about 1 cm squares with the upper and lower faces almost parallel to the (100) (001) planes were obtained with a probability exceeding 50% when NN single crystal particles were synthesized from mixed salts and were subsequently thermal-treated again in Na2CO3-NaCl mixed molten salts under appropriate conditions to remove the Bi element, which is known as the suppression factor of the crystal growth. The average crystal growth rate was 0.6–1.2 mm h−1. Controlling the growth orientation of KNN single crystals produced by the SSCG method using seed crystals other than KTaO3 single crystals was successfully accomplished for the first time.

Substrate orientation influence on nanotwinning in magnetron sputtered CoCrFeMnNi and Ni coatings

This study reveals the influence of crystal orientation on formation of growth twins in magnetron-sputtered coatings. A comparison between materials with low and high stacking fault energy (SFE) was made: CoCrFeMnNi (25 mJ/m2) and Ni (125 mJ/m2). The coatings were grown on a polycrystalline 316L stainless-steel substrate with near-random crystal texture, providing a comprehensive selection of samples on a single substrate. Electron backscatter diffraction was used to identify the film orientation, followed by transmission electron microscopy of selected regions.The presence and density of twins depended on both the material and the growth orientation. For Ni, nanotwins were observed on < 5 % of the substrate grains, on growth directions closest to 〈111〉 . All other film orientations grew epitaxially with a cube-on-cube relationship. For CoCrFeMnNi, nanotwinning was observed on 50 % of the substrate grains, deviating < 35° from 〈111〉 . In the nanotwinned regions, the twin spacing was 10–100 nm for Ni and 2–20 nm for CoCrFeMnNi. The presence of nanotwins increased hardness in both materials. The mechanism behind these differences is discussed, together with other parameters for controlling twin density. Our results show that control of the growth process can be used for nanotwin-engineering in magnetron-sputtered materials with low SFE.

Hexagons on rectangles: Epitaxial graphene on Ru[formula omitted]

Ruthenium is emerging as a promising candidate to replace copper in highly integrated electronics by enabling barrierless metallization in ultrathin interconnects. From this perspective, the study of graphene growth on such surface templates is of paramount importance as a platform for graphene integration in electronic devices. In particular, graphene growth on the Ru(101‾0) surface allows selective growth of different graphene orientations, one-dimensional structures, and reduced substrate interaction compared to the well-established hexagonal Ru(0001) substrate. Real-time growth observations using low-energy electron microscopy and micro-diffraction highlight the influence of substrate symmetry on graphene growth, leading to the formation of rectangular islands with distinct zigzag- or armchair-terminated edges. Bilayer formation on Ru(101‾0) occurs by nucleation of graphene nanoribbons under the monolayer. Micro-spot angle-resolved photoemission spectroscopy shows significantly less charge-transfer doping in these freestanding, zigzag-terminated bilayer graphene nanoribbons, indicating reduced graphene-substrate interaction and hence more effective decoupling as compared to graphene/Ru(0001). Our results show that the growth of graphene on non-hexagonal substrates opens new pathways for tailoring the graphene-substrate interaction at the interface, and thus the properties of graphene beyond the limits imposed by hexagonal substrates.

A generalized numerical model for clonal growth in scleractinian coral colonies.

Coral reefs, vital ecosystems supporting diverse marine life, are primarily shaped by the clonal expansion of coral colonies. Although the principles of coral clonal growth, involving polyp division for spatial extension, are well-understood, numerical modelling efforts are notably scarce in the literature. In this article, we present a parsimonious numerical model based on the cloning of polyps, using five key parameters to simulate a range of coral shapes. The model is agent-based, where each polyp represents an individual. The colony's surface expansion is dictated by the growth mode parameter (s), guiding the preferred growth direction. Varying s facilitates the emulation of diverse coral shapes, including massive, branching, cauliflower, columnar and tabular colonies. Additionally, we introduce a novel approach for self-regulatory branching, inspired by the intricate mesh-like canal system and internode regularity observed in Acropora species. Through a comprehensive sensitivity analysis, we demonstrate the robustness of our model, paving the way for future applications that incorporate environmental factors, such as light and water flow. Coral colonies are known for their high plasticity, and understanding how individual polyps interact with each other and their surroundings to create the reef structure has been a longstanding question in the field. This model offers a powerful framework for studying these interactions, enabling a future implementation of environmental factors and the possibility of identifying the key mechanisms influencing coral colonies' morphogenesis.

Effect of ultra-high temperature treatment on the rolled pure molybdenum for nuclear thermal propulsion

Molybdenum (Mo)-based uranium dioxide (UO2) fuel is considered one of the most promising fuel forms for deep-space exploration. The rolling process has been proposed for the preparation of Mo matrix due to its excellent performance. However, there has been limited research on the ultra-high temperature stability of Mo matrix used in nuclear thermal propulsion (NTP). Therefore, in this study, annealing experiments were carried out on rolled Mo plates within a relatively wide temperature range of 1200 to 2300 °C for 1 h to investigate the effects of temperature on the phase composition, microstructure, and mechanical property. The results showed that, despite the body-centered cubic structure of the Mo plates remaining unchanged without undergoing phase transition after high-temperatures, the intensity of the crystal diffraction peaks experienced a significant increase. The preferred growth orientation shifted from the (110) direction at lower temperatures to the (200) direction at 2300 °C. The grain shape of the rolled Mo plates changed from elongated to equiaxed after annealing, and the grain size increased from the initial 1 μm to tens of microns. No discernible surface pores or fracture bubbles were observed when annealed at 1200 to 2100 °C. However, subsequent annealing at 2300 °C revealed a proliferation of polyhedral bubbles, ranging in size from tens of nanometers to several microns, distributed both in grain boundaries and within grains. Nevertheless, there is no apparent change in the density from 1200 to 2300 °C. Bright-field TEM micrographs show that after annealing at 2300 °C, the dislocation density is significantly reduced, and the dislocation shape evolves from screw dislocation to long and straight line. In addition, the Vickers hardness value of the rolled Mo plates undergoes a significant decrease, from 247.1 to 199.6 Hv, after annealing at 1200 °C. Subsequently, in the temperature range of 1200 to 2300 °C, a gradual decline in the hardness value is observed. This work will deepen our understanding of the high-temperature resistance of rolled Mo plates and provide data to support their applications in ultra-high-temperature conditions.

Microstructure, hardness, and tribological properties of Ni-Co/ SiO2 nanocomposite coating produced through pulsed current electrodeposition

This study investigates the development of Ni-Co/SiO2 nanocomposite coatings on mild steel surface using pulsed-current electrodeposition method. The effects of incorporating SiO2 nanoparticle and varying its concentration on the coatings' microstructure, microhardness, wear resistance, and frictional properties were assessed using field-emission electron microscopy, X-ray diffraction, Vickers microhardness testing, and dry sliding wear tests. The results indicated that the coatings exhibited two-phases of Ni-Co solid solution (α) with a face-centered cubic (FCC) crystal structure and hexagonal Co, a refined crystallite size of approximately 31 nm for Ni-Co and about 25 nm for Ni-Co/SiO2, along with a colony-like morphology that did not show any preferred growth direction. The amount of Ni-Co solid solution increased with the addition of SiO2 nanoparticles. The composite coatings demonstrated enhanced microhardness of 581 HV, which is 52 % greater than that of the Ni-Co coating, as well as improved wear resistance and a reduced friction coefficient compared to the unreinforced alloy coating. However, higher SiO2 content adversely impacted the tribological properties due to nanoparticle agglomeration. Analysis of the worn surfaces revealed a transition from abrasive wear to oxidative wear with increasing applied force for the coatings.

Driving SME growth and learning effectiveness: The role of analyzer orientation, learning capability, and innovation

This study, drawing on the Knowledge-Based View (KBV) and Contingency Theory, explores how analyzer strategic orientation, learning capability, technical innovation, administrative innovation, and SME growth and learning effectiveness are interrelated. Analyzing cross-sectional data from 407 founders, cofounders, and managers of trade and service SMEs in Vietnam’s Southeast Key Economic Region through PLS-SEM, the research demonstrates that analyzer orientation positively impacts both technical and administrative innovation, thereby bolstering SME growth and learning effectiveness. However, learning capability does not significantly impact technical innovation or growth and learning effectiveness. Instead, learning capability negatively affects administrative innovation. Notably, technical and administrative innovations act as mediators between analyzer orientation and SME growth and learning effectiveness. The study provides practical insights tailored for SMEs navigating dynamic market environments like Vietnam, enriching theoretical understanding of SME strategic management within the trade and service sector.

The effect of cooling rate on the precipitation behavior and fracture toughness of the η phase in LDED CoCrFeNiTi high-entropy alloy

Precipitation strengthening is recognized as an effective method for strengthening high-entropy alloys (HEAs) or medium-entropy alloys (MEAs), especially the recently developed CoCrFeNiTi HEA. The η phase plays a crucial role in strengthening CoCrFeNiTix HEAs, though it remains relatively understudied. In this study, CoCrFeNiTi HEA was fabricated by laser directed energy deposition (LDED). The research investigated the effect of cooling rate on the precipitation behavior and fracture toughness of the η phase in non-equilibrium solidified CoCrFeNiTi HEA. The findings revealed that the precipitation of the η phase in the as-deposited LDED sample was restrained, resulting in a very low volume fraction. However, a high-volume-fraction η phase was achieved through annealing at 900 °C for 6 h, followed by air cooling. This approach not only maintained the desired ∼6.2 % volume fraction of the η phase but also prevented its growth and coarsening (∼403 nm), resulting in an optimal combination of microstructure and mechanical properties. The η phase exhibited the Blackburn type orientation relationship with the FCC phase: <11 2‾ 0>η//<1 1‾ 0>FCC and {0001}η//{111}FCC. The L interface of the η phase demonstrated a coherent relationship with the FCC phase ({0001}η//{111}FCC), while the W interface was incoherent with the FCC phase ({11 2‾ 0}η//{1 1‾ 0}FCC). The unique interface characteristics promoted a higher growth rate at the W interface compared to the L interface, leading to the preferred growth of the η phase. The chemical compositions of both the FCC phase and η phase were accurately predicted by experiments and simulations, elucidating the precipitation kinetics of the η phase. When v ≥ vWC, the nucleation and precipitation of the η phase were inhibited. Conversely, when v ≤ vFC, significant coarsening of the η phase occurred. However, when v ≈ vAC, the AC sample exhibited superior mechanical properties, with a microhardness of ∼860 HV and excellent fracture toughness. These findings provide valuable insights and guidance for further enhancement and optimization of HEAs/MEAs strengthened by the η phase.

Discovery of Aloperine as a Potential Antineoplastic Agent for Cholangiocarcinoma Harboring Mutant IDH1.

Intrahepatic cholangiocarcinoma (ICC) is a universally lethal malignancy with increasing incidence. However, ICC patients receive limited benefits from current drugs; therefore, we must urgently explore new drugs for treating ICC. Quinolizidine alkaloids, as essential active ingredients extracted from Sophora alopecuroides Linn, can suppress cancer cell growth via numerous mechanisms and have therapeutic effects on liver-related diseases. However, the impact of quinolizidine alkaloids on intrahepatic cholangiocarcinoma has not been fully studied. In this article, the in vitro anti-ICC activities of six natural quinolizidine alkaloids were explored. Aloperine was the most potent antitumor compound among the tested quinolizidine alkaloids, and it preferentially inhibited RBE cells rather than HCCC-9810 cells. Mechanistically, aloperine can potentially decrease glutamate content by inhibiting the hydrolysis of glutamine, reducing D-2-hydroxyglutarate levels and, consequently, leading to preferential growth inhibition in isocitrate dehydrogenase (IDH)-mutant ICC cells. In addition, aloperine preferentially resensitizes RBE cells to 5-fluorouracil, AGI-5198 and olaparib. This article demonstrates that aloperine shows preferential antitumor effects in intrahepatic cholangiocarcinoma cells harboring the mutant IDH1 by decreasing D-2-hydroxyglutarate, suggesting that aloperine could be used as a lead compound or adjuvant chemotherapy drug to treat ICC harboring the mutant IDH.

Cellular automata-lattice Boltzmann model for polycrystalline solidification with motion of numerous dendrites

A GPU-accelerated cellular automata-lattice Boltzmann combinatorial model is developed for calculating the preferred growth, movement, and collision behavior of equiaxed crystals in supercooled melts of binary alloys. For moving dendrites, the growth is computed in a dynamic grid that grows with the body, and continuous movement is achieved by moving the dynamic grid. The impulse-based method is used for the collision of dendrites to calculate the post-collision velocity. Each module of the model was rigorously benchmarked, proving that the model has good computational accuracy and efficiency. The model was used for modeling the solidification of an Al-3 wt% Cu alloy, simulating the growth of abundant kinematic equiaxed crystals in a rotating flow and the falling and stacking of dendrites in droves and subsequent grain growth during the columnar to equiaxed transition, respectively.

Polyethylene glycol-assisted hydro-solvothermal growth of anisotropic magnetic iron oxides: The role of mixed environment conditions

In this study, an alternative mixed hydro-solvothermal route has been investigated for the synthesis of magnetic iron oxide nanoparticles with anisotropic shape. The synthesis was performed at mild conditions (150 °C) in a water/2-propanol environment, using poly(ethylene glycol) (PEG400) as structure directing agent, sodium thiosulfate as reducing agent, and NaOH as precipitating agent. The resulting systems were characterized by combining morphological, structural, and magnetic techniques. Experimental results clearly demonstrate that magnetite/maghemite nanorods are preferentially obtained in water/PEG400 environment, whereas 2-propanol/PEG400 environment promotes the growth of magnetite/maghemite polyhedral systems. Interestingly, synthesis performed in a mixed hydro-solvothermal (i.e., water/2-propanol) environment favors the preferential growth of hematite phase.

Bonding-Directed Crystallization of Ultra-Long One-Dimensional NbS3 van der Waals Nanowires.

The rediscovery of one-dimensional (1D) and quasi-1D (q-1D) van der Waals (vdW) crystals ushered the realization of nascent physical properties in 1D that are suitable for applications in photonics, electronics, and sensing. However, despite renewed interest in the creation and understanding of the physical properties of 1D and q-1D vdW crystals, the lack of accessible synthetic pathways for growing well-defined nanostructures that extend across several length scales remains. Using the highly anisotropic 1D vdW NbS3-I crystal as a model phase, we present a catalyst-free and bottom-up synthetic approach to access ultralong nanowires, with lengths reaching up to 7.9 mm and with uniform thicknesses ranging from 13 to 160 nm between individual nanowires. Control over the synthetic parameters enabled the modulation of intra- and interchain growth modalities to selectively yield only 1D nanowires or quasi-2D nanoribbons. Comparative synthetic and density functional theory (DFT) studies with a closely related nondimerized phase, ZrS3, show that the unusual preferential growth along 1D can be correlated to the strongly anisotropic bonding and dimeric nature of NbS3-I.

Machine Learning-Enabled performance exploration to unveil the potential of AuCuSe4 in thermophotovoltaic cell

In this work, AuCuSe4 direct bandgap (Eg = 0.52 eV) semiconductor has been examined as a thermophotovoltaic (TPV) material. Initially, the electronic structure of AuCuSe4 compound has been investigated using first-principles calculations. The study reveals a semiconducting nature of AuCuSe4 with a narrow bandgap computed by DFT-MBJ (Density Functional Theory with Modified Becke-Johnson) method which is lower than the experimental value. The optical properties show significant aniso-tropic by AuCuSe4 absorption in the solar spectrum, favoring TPV growth orientation. Subsequently, a single-junction AuCuSe4 TPV cell has been presented employing a device transport model with an n-p structure, operating at the black body and cell temperatures of 1538 K and 300 K, respectively. Notably, machine learning (ML) techniques are utilized to investigate the significance of each parameter in the model, enhancing the understanding of the system’s behavior and design optimization. Through optimization, the performance of the TPV cell has been enhanced, resulting in an efficiency of 11.56 %, accompanied by the current at short circuit, JSC=9.22 A/cm2, voltage at the open circuit, VOC=0.49 V, and Fill factor, FF=80 %. These findings suggest that AuCuSe4 holds promise as a suitable material for creating high-performing TPV cells.

Remote vapor-phase dual alkali halide salts assisted quasi-van der Waals epitaxy of m-phase ZrO2 thin films with high dielectric constant and stable flexible properties

High-κ dielectric constant and wideband gap of ZrO2 material render it as an excellent candidate for transistor gate dielectric layers. However, current reported synthesis techniques suffer the problems of high precursor volatilization rate, ultrasmall grains with low dielectric constant, and high leakage current, which largely impede its application in electronic devices. Here, the quasi-van der Waals epitaxy growth of compact m-phase ZrO2 thin films has been developed, in which the stable supply of Zr source is realized by the tuned sublimation of ZrC powder with remote vapor-phase dual halide salts assistant. The formation of m-phase ZrO2 is due to the lower Gibbs free energy, in which the crystal nucleates at the etched hole edges of mica substrate, thus forming hexagonal shape polycrystal grains and merging as the continuous thin films. The microstructures and Raman spectrum characterization reveal the two dominated growth orientations and good crystal qualities, which indicate the uniform dielectric constant. The excellent growth reproducibility could be easily adapted to thin metal substrates, such as tungsten, molybdenum, and stainless steel, where the adhesion strength is strong because of the higher density of interfacial chemical bonding. Meanwhile, the metal–insulator–metal flexible capacitors show the high dielectric constant of 23–26 and low leakage current density of 10−4 A/cm2 at large voltage and only exhibit the decreased capacitance density of 7% after several hundred bending cycles. Our work paves a way to achieve the high-quality dielectric thin films on various substrates by the unique chemical vapor deposition design strategy.

Oxides Induced Preferential Growth of {110} Planes for Superior Performance Single-Crystal LiMn2O4 through Solid-State Process.

Polycrystalline lithium manganese oxide (LMO) is known to suffer from severe surface structure degradation and electrochemical polarization due to its mixed crystal plane orientations. A hexagonal prism single-crystal LMO (LMOS-HP), engineered through the SrO-induced preferential growth effect, features the most stable {111} top surfaces and the fastest Li+ diffusion {110} side surfaces, effectively addressing these challenges. Consequently, LMOS-HP exhibits superior electrochemical capability, with only 0.021% capacity fading per cycle after 500 cycles and achieves a discharge capacity of 81.9 mAh g-1 at 20C. This innovative design offers a promising approach for tuning surface crystal orientation to improve performance.