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A comprehensive analysis of Bi2O2CO3 nanosheets, which were synthesized using nanosecond‐pulsed discharges in water between bismuth electrodes, was conducted in order to investigate the crystallographic features of this material. Electron diffraction, X‐ray diffraction and electron energy‐loss spectrometry techniques revealed the presence of a stoichiometric tetragonal Bi2O2CO3 structure, labelled BOC in this study. It crystallizes in the body‐centred tetragonal Bravais lattice and belongs to the I4/mmm space group (No. 139), with the following lattice parameters: a = 3.91, c = 13.77 Å. The nanosheets adopt square shapes. This shape is dictated by the symmetry elements of its point group (4/mmm) under the prevailing local conditions. From the energetic point of view, this shape, dictated by the 4/m2/m2/m point group and therefore a pinacoid, corresponds to an absolute extremum, an indicator of the stability of these BOC nanosheets. Most nanosheets are crossed by equal‐inclination fringes or bend contours. These bend contours reflect the fact that the BOC nanosheets contain crystal defects and/or are so thin that they bend elastically, leading to rotation of the lattice planes towards the diffracting Bragg position. The diffraction patterns corresponding to bend contours intersecting along the [001] zone axis have been studied in detail. Extra reflections are superimposed on the diffraction pattern of the BOC crystallographic structure. These extra reflections are essentially attributed to two phenomena: multiple diffraction and local disorder–order transformations of the BOC crystal structure, passing from a body‐centred tetragonal to a primitive Bravais lattice. A mechanism related to the ledge mechanism (kinks and jogs), explaining the formation of nanosheets in a metallic matrix, has been adapted and proposed for the formation of BOC nanosheets in water. When the nanosheets are removed from the water, they become carbonated once in the air, leading to the formation of BOC that inherits the nanosheet morphology. [ABSTRACT FROM AUTHOR]

The topological features of the formation of (Co40Fe40B20)15(LiNbO3)85 composite films deposited by ion-beam method on a metal electrode Cr/Cu/Cr has been investigated. The presence of a dielectric layer between the upper Cr layer and the CoFe–LiNbO3 film with a thickness of dox ≈ 15 nm has been established. The difference in the size of granules near the amorphous layer and in the volume of the film has been shown. A model of the formation of (Co40Fe40B20)x (LiNbO3)100 –x nanocomposite film at the initial stage of growth has been proposed. It has been shown that the formation of α-LiNbO3 layer on the chrome metal film surface is possible with the realization of island and layer-by-layer growth mechanisms for various phases of the composite. [ABSTRACT FROM AUTHOR]

The growth of epitaxial thin films from the Ruddlesden–Popper series of strontium iridates by magnetron sputtering is analyzed. It was found that, even using a non-stoichiometric target, the films formed under various conditions were consistently of the perovskite-like n = ∞ SrIrO3 phase, with no evidence of other RP series phases. A detailed inspection of the temperature–oxygen phase diagram underscored that kinetics mechanisms prevail over thermodynamics considerations. The analysis of the angular distribution of sputtered iridium and strontium species indicated clearly different spatial distribution patterns. Additionally, significant backsputtering was detected at elevated temperatures. Thus, it is assumed that the interplay between these two kinetic phenomena is at the origin of the preferential nucleation of the SrIrO3 phase. In addition, strategies for controlling cation stoichiometry off-axis have also been explored. Finally, the long-term stability of the films has been demonstrated. [ABSTRACT FROM AUTHOR]

Ultrasound crystallization (UC) technique was previously proposed to solve the issues caused by the acidic ammonium salts crystallization of vanadium. In this work, the influence of various parameters on vanadium crystallization characteristics were detailedly investigated. Results showed that high vanadium precipitation ratio (99.67%) and V2O5 purity (99.50%) of the final products can be obtained under the conditions of ultrasonic power of 600 W, initial pH value of 2.0, reaction temperature of 95 °C, ammonium salt addition coefficient of 0.5, reaction duration of 5 min and vanadium concentration of 20 g/L. Moreover, the NH4+ content in the supernatant liquid was notably reduced to 1.08 g/L. Crystallization kinetic analysis manifests that the crystallization rate constant augments with the increasing temperature, and the activation energy and pre-exponential factor is 71.87 kJ/mol and 7.44 × 109, respectively. Ultrasound enhances the collision frequency between NH4+ and vanadium ions, further improving the crystallization rate of the (NH4)2V6O16 crystals. Meanwhile, ultrasound induces a secondary nucleation, which would promote the intercalation among small flakes and further improves the nucleation and growth of the (NH4)2V6O16 crystals. Scanning electron microscopy analysis demonstrates that the flaky crystals are firstly formed, then a part of flakes gradually intercalate with each other, and finally most of the lamellar crystals complete the intercalation process. Meanwhile, selected area electron diffraction verifies the single crystalline characteristic of the micron-flakes, which grows along the (010) crystal plane. This work will lay theoretical and technical basis for UC technique appliance and promote the progress of the vanadium extraction industry.

Constructing resistive layer with novel structure holds great potential in upgrading electromagnetic properties of soft magnetic materials in a wide frequency range. In this work, FeNi@SiO2 composites with controllable core–shell structures, including 2D-type laminar shell and 3D-type raspberry-like shell, were fabricated by modified Stöber method. The structure of SiO2 shell depends highly on the concentration of tetraethyl orthosilicate (TEOS). In detail, a laminar shell can be formed at low TEOS concentration, owing to slow condensation. While at high TEOS concentration, heterogeneous growth on powder surface and homogeneous growth in solution of silica networks are significantly accelerated, resulting in the formation of the raspberry-like shell. Improved electromagnetic performance of FeNi@SiO2 cores at 2 MHz, including high resistivity, low eddy current loss, and low loss factor, should be ascribed to the unique raspberry-like shell structure. Meanwhile, raspberry-like shell also contributes to enhanced attenuation and acceptable impedance matching in GHz range. Consequently, a wide effective absorption bandwidth of 8.92 GHz can be achieved at a thin thickness of 1.85 mm. This work provides deep insights into the growth mechanism of different SiO2 shells and sheds new light on the design of high-performance soft magnetic composites working in different frequency bands.

Nanomaterials are substances that have at least one dimension that falls within the three-dimensional nanoscale range or fundamental structural components made of substances that fall inside this range. Micro-nano 3D printing technology can realize the processing of 3D micro-nano structures with nanometer precision and has broad application prospects in many fields. Metals and polymers can be easily connected through bonding reactions to obtain metal-metal or covalent bonds in 3D printing. These potent chemical bonds make 3D-printed structures stable, and 3D printing of metals and plastics is developing rapidly. The review focuses on the latest developments in unique composite nanomaterials for different field applications, comprising nanomaterials and 3D printing technology. A summary of the mechanisms, functional characteristics, benefits, drawbacks, and applications of various nanomaterials used in scientific 3D printing includes metal-based nanomaterials, metal-organic frameworks, upconversion nanoparticles, and lipid-based nanoparticles. Finally, this study presents an overview and highlights the issues that need to be resolved for nanomaterials to continue to be developed for the advantages of 3D printing.

Cesium lead triiodide (CsPbI3) inorganic perovskite possesses excellent thermal stability and matched bandgap for silicon‐based tandem photovoltaics. The solution method with high‐temperature annealing process for CsPbI3 film preparation creates challenges to scalable application and conformal growth on the textured silicon. Although additives can decrease the annealing temperature, it will introduce undesired organic components and increase material cost. Thermal co‐evaporation for CsPbI3 has intrinsic advantages to overcome these issues, but the vague growth mechanism impedes the photovoltaic device development. In this study, γ‐CsPbI3 films are directly obtained through co‐evaporation at 50 °C without any additives or high‐temperature post‐annealing. Focusing on the molecular thermodynamic calculations, it is proposed that the unique kinetic energy of evaporated molecules and the in‐situ substrate thermal energy synergistically provide the energy prerequisite for γ‐CsPbI3 formation. Furthermore, the γ phase stabilization is clarified by the crystal grain size effect with regard to the Gibbs free energy difference between the γ and δ phases, which is adjusted through substrate temperature and evaporation rate. The obtained p‐i‐n device realizes an efficiency of 12.75%, which is the highest value for the thermally evaporated γ‐CsPbI3 photovoltaics at low temperature without additives. This study deepens the understanding of thermal evaporation process, benefiting to high‐performance CsPbI3‐textured silicon tandem photovoltaics. [ABSTRACT FROM AUTHOR]

Nanomaterials are substances that have at least one dimension that falls within the three-dimensional nanoscale range or fundamental structural components made of substances that fall inside this range. Micro-nano 3D printing technology can realize the processing of 3D micro-nano structures with nanometer precision and has broad application prospects in many fields. Metals and polymers can be easily connected through bonding reactions to obtain metal-metal or covalent bonds in 3D printing. These potent chemical bonds make 3D-printed structures stable, and 3D printing of metals and plastics is developing rapidly. The review focuses on the latest developments in unique composite nanomaterials for different field applications, comprising nanomaterials and 3D printing technology. A summary of the mechanisms, functional characteristics, benefits, drawbacks, and applications of various nanomaterials used in scientific 3D printing includes metal-based nanomaterials, metal-organic frameworks, upconversion nanoparticles, and lipid-based nanoparticles. Finally, this study presents an overview and highlights the issues that need to be resolved for nanomaterials to continue to be developed for the advantages of 3D printing. [ABSTRACT FROM AUTHOR]

The chemical formula of basic zinc chloride is Zn5(OH)8Cl2 · H2O (denoted as ZHC). It is a new type of zinc source additive, widely used in the feed industry. In this article, micron‐sized hexagonal flake ZHC with a diameter of 10–60 µm is directly prepared by ammonia precipitation method using ZnCl2 as raw material. The products are characterized and analyzed by X‐ray diffraction, scanning electron microscopy, and laser particle size analyzer. The effects of reaction temperature, ammonia flow rate, aging time, and reactant concentration on the product morphology are studied. Under the optimum reaction conditions, the ZnCl2 concentration is 2.0 mol L−1, NH3 flow rate is 300 mL min−1, the reaction time is 1 h, the reaction temperature is 80 °C, and the aging time is 5 h. Lastly, the yield reaches 49.06%. The growth habit of ZHC is theoretically analyzed by the Morphology program. The calculation results are in good agreement with the experimental results. The change of (003) crystal plane exposure caused by temperature is an important reason for the non‐ideality of macroscopic morphology. [ABSTRACT FROM AUTHOR]

The solid–electrolyte interphase (SEI) in lithium‐ion batteries is mainly built during cell formation. The SEI significantly influences safety, aging, and performance. Due to the manifold influential factors, it is time‐consuming to systematically optimize the cell formation. Herein, a novel procedure to characterize the SEI growth during the first cycle of formation with low experimental effort is introduced. Coin cells in a three‐electrode setup are tested under pseudo‐open‐circuit conditions. By evaluating the differential voltage, the capacity loss due to SEI formation during the first cycle is estimated. The identification of the SEI growth curve is carried out using various methods, which are compared in detail. The approach is exemplary applied to compare different electrolytes. It is shown that the approach can be used to parameterize SEI growth models. An analysis of these models indicates that the SEI growth can be explained by a combination of two growth mechanisms, that is, interstitial diffusion and electron tunneling, while the latter is dominant in the beginning of the formation. Further, based on the results it is suggested that the transition between these mechanisms is influenced by the electrolyte. [ABSTRACT FROM AUTHOR]

The growth of epitaxial thin films from the Ruddlesden–Popper series of strontium iridates by magnetron sputtering is analyzed. It was found that, even using a non-stoichiometric target, the films formed under various conditions were consistently of the perovskite-like n = ∞ SrIrO3 phase, with no evidence of other RP series phases. A detailed inspection of the temperature–oxygen phase diagram underscored that kinetics mechanisms prevail over thermodynamics considerations. The analysis of the angular distribution of sputtered iridium and strontium species indicated clearly different spatial distribution patterns. Additionally, significant backsputtering was detected at elevated temperatures. Thus, it is assumed that the interplay between these two kinetic phenomena is at the origin of the preferential nucleation of the SrIrO3 phase. In addition, strategies for controlling cation stoichiometry off-axis have also been explored. Finally, the long-term stability of the films has been demonstrated.

The effective identification of the active catalytic phase is essential to elucidate the growth mechanism of boron nitride nanotubes (BNNTs) and realize their controllable and scalable synthesis. However, owing to the complexity of chemical reactions during BNNT growth via chemical vapor deposition (CVD) and the lack of techniques for in situ characterization at high temperatures (1100–1300 °C), identifying the true catalyst during BNNT growth is challenging. Herein, an aluminum (Al)‐based active catalyst for BNNT growth via CVD is investigated. The initial Al2O3 nanoparticle catalyst precursor is transformed into an Al‐B phase prior to BNNT growth. Based on our density functional theory‐based molecular dynamic simulations of BNNT nucleation, AlB x (x = 1.5 to 2) shows catalytic activity for the formation of BN chains and BN six‐membered rings. Confirmatory experiments demonstrate that AlB2 is the active Al‐based catalyst during BNNT growth. A nanocomposite is prepared from cellulose nanocrystal, and purified BNNTs exhibited a high in‐plane thermal conductivity of 13.33 W m−1 K−1 at 20 wt% BNNTs. A further application for light‐emitting diode chip cooling demonstrates excellent heat‐dissipation performance of the nanocomposite film. Thus, this study can guide the controllable synthesis of high‐quality BNNTs and facilitate their use in thermal interface materials.

In this paper, Cr7C3 coating is prepared on porous carbon paper by the disproportionation reaction of Cr2+ in NaCl–KCl molten salt at 800–900 °C for 40–80 min. Effects of the molar ratio of chromium powders, temperature, and reaction time are investigated. The composition and microstructure of the coating are characterized by X‐ray diffraction and scanning electron microscopy. Finally, the growth mechanism of Cr7C3 coating from the perspective of thermodynamics and kinetics is discussed. [ABSTRACT FROM AUTHOR]

This study investigated the growth mechanism of microarc oxidation ceramic coatings on AZ91D magnesium alloy by sequentially treating it in silicate and zirconate electrolyte systems. The distribution patterns of Si and Zr elements were examined to understand the growth mechanism. The results showed that the distribution of Si and Zr elements in the SZ ceramic coatings changed with increasing termination voltage of microarc oxidation. The growth mechanism of microarc oxidation ceramic coatings on magnesium alloys involved the reaction between Si and Zr elements from the electrolyte and Mg elements from the substrate to form molten oxides under the high-temperature and high-pressure conditions of microarc oxidation discharge. At lower termination voltages, some of the molten oxides remained near the discharge channels or the film/substrate interface, resulting in inward growth of the ceramic coating. As the termination voltage increased, some of the molten oxides were ejected outward through the discharge channels, facilitating outward growth of the ceramic coating. The inclusion of silicon elements compared to zirconium elements will significantly increase the concentration of oxygen vacancies in the ceramic membrane, enhancing the electrical conductivity of the ceramic membrane while reducing its corrosion resistance. [ABSTRACT FROM AUTHOR]

Alcohol chemical vapor deposition (ACVD) was established as one of the most promising methods for single-walled carbon nanotube (SWCNT) growth almost two decades ago however the mechanisms behind its success remain elusive. To unveil the mechanism of SWCNT growth via ACVD, we employed density functional tight binding molecular dynamics simulations, supplying ethanol to a Fe nanoparticle. Here we demonstrate the oxidation of the Fe catalyst with varying supply rates of ethanol and how the catalyst composition is controlled by the reaction pathways mediated by the hydroxyl OH radical. Following ethanol dissociation on Fe and subsequent O dissolution, the catalyst becomes oxidized and the mobility and availability of Fe to bond with C are reduced. However, SWCNT growth is promoted via the key reaction pathways of the hydroxyl H; controlling the catalyst composition through the formation and release of H 2 O and H 2. These reaction pathways also demonstrate how active growth species such as ethylene can be formed preferentially to ethane from ethanol dissociation. This work provides important insight into the mechanism of how the catalyst composition changes during ACVD and can be extended to understand the catalyst nature during other O-assisted SWCNT growth processes such as H 2 O-assisted supergrowth and CO/CO 2 -promoted growth. [Display omitted] [ABSTRACT FROM AUTHOR]

Protein crystallization was discovered by chance nearly 200 years ago and was developed in the late nineteenth century as a powerful purification tool, and a demonstration of chemical purity. The crystallization of proteins, nucleic acids, and large biological complexes, such as viruses, depends on the creation of a solution that is supersaturated in the macromolecule, but exhibits conditions that do not significantly perturb its natural state. Supersaturation is produced through the addition of mild precipitating agents such as neutral salts or polymers, and by manipulation of various parameters that include temperature, ionic strength, and pH. Also important in the crystallization process are factors that can affect the structural state of the macromolecule, such as metal ions, inhibitors, cofactors, or other conventional small molecules. A variety of approaches have been developed that combine the spectrum of factors that effect and promote crystallization, and among the most widely used are vapor diffusion, dialysis, batch, and liquid-liquid diffusion. Successes in macromolecular crystallization have multiplied rapidly in recent years due to the advent of practical, easy-to-use screening kits, and the application of laboratory robotics.

Revealing the internal structure of diamonds is key to understanding the general regularities of crystal growth and dissolution. This paper presents and summarizes data on the internal structure of diamonds of different morphological types, colors and defect-impurity composition. In order to provide a comprehensive explanation of the stages of diamond growth, crystals and plates were observed, and panchromatic cathodoluminescence and photoluminescence techniques were applied. This article considers the mechanism of tangential growth from existing surfaces (regeneration growth) as an intermediate stage between normal and tangential crystal growth. The regeneration growth is very fast due to the absence of the limiting stage-nucleation of a new atomic layer. Cuboid diamonds were refaceted to stepped octahedrons by the regeneration growth mechanism. A schematic model of crystal habit transformation due to regeneration growth explains the internal structure of crystals in connection with their morphology and thermal history. The main variants of regeneration stage and its morphological manifestations were demonstrated. Most diamonds pass through the regeneration stage, and in many cases, it was a stage of growth termination. [ABSTRACT FROM AUTHOR]

Study on potential mechanisms influencing the growth of raspberry and strawberry plants showed that the most active was Bacillus sp. strain AF75BC producing IAA and siderophores, and having the ability to release phosphorus. The latter feature was also present in the strains Sp115AD (B. subtilis) and SP116AC (Paenibacillus polymyxa). Two of the tested strains: SP116AC and JaFGU (Lysobacter sp.) showed the ability to fix atmospheric nitrogen, while the AF75AB2 (Bacillus sp.) produced siderophores and IAA. All strains showed an antagonism toward the most important pathogens of strawberry and raspberry, i.e. Verticillium dahliae, Botrytis cinerea, Phytophthora cactorum and Colletotrichum acutatum, limiting their growth to a different extent on the PDA medium. Inoculation of raspberry roots with the tested bacteria resulted in an increase of some growth parameters of their above-ground part in cv. Poemat. In the case of cv. Polana, a significant increase was found only in the chlorophyll content in the leaves. All the inoculants caused an increase in dry mass of roots in cv. Polana, and in cv. Poemat similar effect was observed after applying Inoculants 1 and 3. The treatments of strawberry roots with any of the inoculants resulted in a significant increase in the total leaf surface area in cv. Rumba, but they had no effect on the chlorophyll content in the leaves of either cultivar. All the inoculants significantly increased the total length of roots and their total surface area in cv. Rumba. This parameter also increased in cv. Elsanta, and the number of root tips also significantly increased in this cultivar. Our study showed that the tested inocula is a promising alternative as a bio-fertilizer for small fruit production in sustainable and organic agricultural systems. [ABSTRACT FROM AUTHOR]

Study on potential mechanisms influencing the growth of raspberry and strawberry plants showed that the most active was Bacillus sp. strain AF75BC producing IAA and siderophores, and having the ability to release phosphorus. The latter feature was also present in the strains Sp115AD (B. subtilis) and SP116AC (Paenibacillus polymyxa). Two of the tested strains: SP116AC and JaFGU (Lysobacter sp.) showed the ability to fix atmospheric nitrogen, while the AF75AB2 (Bacillus sp.) produced siderophores and IAA. All strains showed an antagonism toward the most important pathogens of strawberry and raspberry, i.e. Verticillium dahliae, Botrytis cinerea, Phytophthora cactorum and Colletotrichum acutatum, limiting their growth to a different extent on the PDA medium. Inoculation of raspberry roots with the tested bacteria resulted in an increase of some growth parameters of their above-ground part in cv. Poemat. In the case of cv. Polana, a significant increase was found only in the chlorophyll content in the leaves. All the inoculants caused an increase in dry mass of roots in cv. Polana, and in cv. Poemat similar effect was observed after applying Inoculants 1 and 3. The treatments of strawberry roots with any of the inoculants resulted in a significant increase in the total leaf surface area in cv. Rumba, but they had no effect on the chlorophyll content in the leaves of either cultivar. All the inoculants significantly increased the total length of roots and their total surface area in cv. Rumba. This parameter also increased in cv. Elsanta, and the number of root tips also significantly increased in this cultivar. Our study showed that the tested inocula is a promising alternative as a bio-fertilizer for small fruit production in sustainable and organic agricultural systems.

• The lower part of the Fengjiawan Formation contains abundant stromatolitic dolostones that possess well-preserved primary structures. • The depositional environment was an open shallow marine associated with a passive continental margin setting. • The stromatolitic dolostones are characterized by suboxic environment with minimal detritus contamination and weak post-depositional alteration. • Multiple depositional factors contributed to the growth and excellent preservation of the stromatolite-dominated microbialites. Stromatolites in the lower part of the Early Mesoproterozoic Fengjiawan Formation in the southern North China Craton (NCC) contain abundant microbial dolostones with well-preserved primary structures. This study comprehensively investigates the macromorphological, petrographical, mineralogical, and geochemical characteristics of these pure stromatolite-dominated microbialites for the first time. The results reveal diverse macromorphological structures distributed from the bottom to the top as conical (lower intertidal to upper subtidal zones), hemispherical domal (lower supratidal zone), spherical domal (upper to middle intertidal zone), and more abundant columnar (upper to middle subtidal zone) stromatolites. The mineral composition of these stromatolites indicates that they are pure dolostones, predominantly consisting of dolomite (avg. 94.24 wt%). These stromatolite-dominated microbialites were subjected to minimal detrital contamination and weak post-depositional alteration as documented by different geochemical multiproxy evaluations. This indicates that they have effectively retained the composition of the seawater in which they were initially formed. Geochemical indicators, such as Y/Ho, La/La*, Gd/Gd* and Ce/Ce* strongly suggest deposition of the stromatolites in an open shallow marine environment characterized by a passive continental margin setting. Different elemental ratios, such as Ce/Ce*, Mo EF , U EF , Mo EF /U EF , imply the stromatolites formation under a suboxic redox environment, where the photosynthesis of cyanobacteria likely played a significant role in the slight oxygenation of the seawater during their formation. These oxygenation levels decreased as water depth increased, with more nutrient supply promoting from deeper waters. The formation and growth of the stromatolite-dominated microbialites were significantly influenced by various depositional conditions, including sea level fluctuations, biological processes, suboxic redox environment, low detritus contamination, and weak post-depositional alteration. These conditions all contributed to the excellent preservation of the Fengjiawan Formation stromatolites, providing valuable insights into deep time microbial carbonates. [ABSTRACT FROM AUTHOR]

A novel quasi-continuous network reinforced structure that consists of borides and carbides in B 4 C/TiAl matrix composites was innovatively designed for the strengthening at high temperatures. Simultaneously, impacts of such reinforced structures on microstructures and mechanical properties of the composites have been unveiled. TiAl matrix units in B 4 C/TiAl composites are duplex microstructures which are composed of (α 2 +γ) colonies and γ grains. The ascent of B 4 C contents triggers off the formation of network reinforced structures in the layers of TiAl matrix units. With B 4 C contents increasing to 0.1 wt%, elasticity modulus and ultimate compressive strengths of B 4 C/TiAl composites are upgraded from 10.944 GPa and 723.10 MPa to 16.052 GPa and 774.611 MPa. As B 4 C contents reach at 5.0 wt%, elasticity modulus and ultimate compressive strengths further soar to 17.244 GPa and 799.19 MPa. Borides and carbides within the quasi-continuous network reinforced structures are unfolded as stripe and needle shaped TiB with B27 structure and Ti 2 AlC particles with MAX structure. Parts of Ti 2 AlC particles take TiB as cores to nucleate and grow. Moreover, TiC phases usually act as the cores for the nucleation of Ti 2 AlC particles. The orientation relationships of such reinforcements represent as [011] TiC //[010] TiB , (1–11)[011] TiC //(0006) [-2110] Ti2AlC , [100] TiB //[0001] Ti2AlC , [010] TiB //[-2110] Ti2AlC and [001] TiB //[01–10] Ti2AlC. The fractures of TiB are usually along or perpendicular to [010] TiB direction. Meanwhile, the fracture surfaces of TiB are always parallel to (100) TiB or (010) TiB planes. Additionally, dislocations slip through Ti 2 AlC particles and lead to separation and sliding of staking planes (0001) Ti2AlC within Ti 2 AlC lattices. TiB and Ti 2 AlC with alternative distribution can stabilize the network reinforced structures and upgrade properties of B 4 C/TiAl composites. [ABSTRACT FROM AUTHOR]

The large‐area synthesis of high‐quality MoS2 plays an important role in realizing industrial applications of optoelectronics, nanoelectronics, and flexible devices. However, current techniques for chemical vapor deposition (CVD)‐grown MoS2 require a high synthetic temperature and a transfer process, which limits its utilization in device fabrications. Here, the direct synthesis of high‐quality monolayer MoS2 with the domain size up to 120 µm by metal‐organic CVD (MOCVD) at a temperature of 320 °C is reported. Owing to the low‐substrate temperature, the MOCVD‐grown MoS2 exhibits low impurity doping and nearly unstrained properties on the growth substrate, demonstrating enhanced electronic performance with high electron mobility of 68.3 cm2 V−1 s−1 at room temperature. In addition, by tuning the precursor ratio, a better understanding of the MoS2 growth process via a geometric model of the MoS2 flake shape, is developed, which can provide further guidance for the synthesis of 2D materials. [ABSTRACT FROM AUTHOR]

With advances in nanotechnology, nanowires have gained worldwide attention because of their novel properties and promising applications. Among them, silicon nitride (Si 3 N 4) nanowires have attracted increasing attention due to their excellent performance and huge application potential. In this review, various synthesis methods of Si 3 N 4 nanowires are introduced in detail, and then the growth mechanisms are also stated. Subsequently, the novel properties of Si 3 N 4 nanowires including mechanical, optical, electrical, thermal, and wetting performance are highlighted. Applications corresponding to performance are also summarized later, such as composites, field emitters, field-effect transistors (FETs), photodetectors, photocatalysts, and microwave absorbers. Finally, the contents of this article are concluded and outlooks of future research directions are stated. This article reviews the recent advances and provides the prospects and challenges of Si 3 N 4 nanowires. [Display omitted] • The designed synthesis methods and growth mechanisms of Si 3 N 4 nanowires were summarized. • The novel properties of Si 3 N 4 nanowires were highlighted. • The potential applications of Si 3 N 4 nanowires were indicated. • The challenges and opportunities of Si 3 N 4 nanowires were proposed. [ABSTRACT FROM AUTHOR]

Calcium oxalate (CaOx) is the major phase in kidney stones and the primary calcium storage medium in plants. CaOx can form crystals with different lattice types, water contents, and crystal structures. However, the conditions and mechanisms leading to nucleation of particular CaOx crystals are unclear. Here, liquid-cell transmission electron microscopy and atomistic molecular dynamics simulations are used to study in situ CaOx nucleation at different conditions. The observations reveal that rhombohedral CaOx monohydrate (COM) can nucleate via a classical pathway, while square COM can nucleate via a non-classical multiphase pathway. Citrate, a kidney stone inhibitor, increases the solubility of calcium by forming calcium-citrate complexes and blocks oxalate ions from approaching calcium. The presence of multiple hydrated ionic species draws additional water molecules into nucleating CaOx dihydrate crystals. These findings reveal that by controlling the nucleation pathways one can determine the macroscale crystal structure, hydration state, and morphology of CaOx. [ABSTRACT FROM AUTHOR]

Material formation mechanisms and their selective realization must be well understood for the development of new materials for advanced technologies. Since nanomaterials demonstrate higher specific surface energies compared to their corresponding bulk materials, the homoepitaxial growth of nanomaterials on bulk materials is not thermodynamically favorable. We observed the homoepitaxial growth of nanowires with constant outer diameters on bulk materials in two different, solution-based growth systems. We also suggested potential mechanisms of the spontaneous and homoepitaxial growth of the ZnO nanostructures based on the characterization results. The first key factor for favorable growth was the crystal facet stabilization effect of capping agents during the early stages of growth. The second factor was the change in the dominant growth mode during the reaction in a closed system. The spontaneous, homoepitaxial growth of nanomaterials enables the realization of unprecedented, complex, hierarchical, single-crystalline structures required for future technologies. [ABSTRACT FROM AUTHOR]

Abstract Epitaxial growth of III‐nitrides on 2D materials enables the realization of flexible optoelectronic devices for next‐generation wearable applications. Unfortunately, it is difficult to obtain high‐quality III‐nitride epilayers on 2D materials such as hexagonal BN (h‐BN) due to different atom hybridizations. Here, the epitaxy of single‐crystalline GaN films on the chemically activated h‐BN/Al2O3 substrates is reported, paying attention to interface atomic configuration. It is found that chemical‐activated h‐BN provides BON and NO bonds, where the latter ones act as effective artificial dangling bonds for following GaN nucleation, leading to Ga‐polar GaN films with a flat surface. The h‐BN is also found to be effective in modifying the compressive strain in GaN film and thus improves indium incorporation during the growth of InGaN quantum wells, resulting in the achievement of pure green light‐emitting diodes. This work provides an effective way for III‐nitrides epitaxy on h‐BN and a possible route to overcome the epitaxial bottleneck of high indium content III‐nitride light‐emitting devices.

Abstract Two-dimensional (2D) transition metal dichalcogenides (TMDs) have stimulated the modern technology due to their unique and tunable electronic, optical, and chemical properties. Therefore, it is very important to study the control parameters for material preparation to achieve high quality thin films for modern electronics, as the performance of TMDs-based device largely depends on their layer number, grain size, orientation, and morphology. Among the synthesis methods, chemical vapor deposition (CVD) is an excellent technique, vastly used to grow controlled layer of 2D materials in recent years. In this review, we discuss the different growth routes and mechanisms to synthesize high quality large size TMDs using CVD method. We highlight the recent advances in the controlled growth of mono- and few-layer TMDs materials by varying different growth parameters. Finally, different strategies to control the grain size, boundaries, orientation, morphology and their application for various field of are also thoroughly discussed.

Nanostructures are playing significant roles in the development of new functions and the enhancement of the existing functions of industrial devices such as sensors, transistors, diodes, lithium-ion batteries, and photovoltaic cells, due to their piezoelectricity, biocompatibility, and pyroelectrical characteristics. This research focused on the review of the characteristics of different nanostructures and nanomaterials such as ZnO, ZnS, MoS2, GO, TiO2, SnO2, and Fe2O3, their fabrication techniques, growth mechanisms, and applications. The factors affecting the growth mechanisms, the crystallographic natures, growth models of anisotropic nanostructures, and growth of nanocrystals, were also highlighted in this research. The existence of lattice mismatch, differential thermal expansion, and high deposition temperature, have affected uniform deposition of nanoparticles on substrates and caused heteroepitaxy, which has resulted in defective nanostructures. Although heteroepitaxy has negatively affected the characteristics and potential applications of nanostructures, it has also opened new research frontiers for potential new applications of nanostructures. The use of nanostructures for gas sensing is attributed to the high specific area, change of resistance on exposure to gases, and high photoconduction abilities, while the photon-carrier collection abilities and anti-reflectance qualities are vital for solar photovoltaic cells. Nanostructures have also been used as coating pigments to prevent corrosion of facilities, reduce urban heat islands and energy consumptions, due to the near infrared (NIR) reflective characteristics.

Three‐dimensional graphene (3D‐Gr) has a unique construction and special thermal features, thus providing promising opportunities for application in thermal management devices. Herein, 2D graphene (2D‐Gr) is introduced as an interfacial layer in plasma‐assisted chemical vapor deposition (PACVD); then, in situ growth of 3D‐Gr is achieved on a germanium (Ge) substrate. Systematic experiments are conducted to study and analyze the synthesis mechanism. Finally, the obtained 2D/3D‐Gr integrations are developed for the application in high‐performance thermal management. By measuring and comparing the thermal heating performance of the pure 3D‐Gr device and 2D/3D‐Gr device, it is determined that the combination of 3D‐Gr with 2D‐Gr significantly improves their thermal heating behavior, benefiting from the improved quality of 3D‐Gr assisted by the 2D‐Gr interfacial layer. The investigations offer an effective strategy for synthesizing high‐quality 3D‐Gr and 2D/3D‐Gr integrations, which pave the way for the development of high‐performance thermal management devices. [ABSTRACT FROM AUTHOR]

Graphene-based cones with nanosized apex can be obtained by means of a high temperature pyrolytic carbon deposition process using methane and hydrogen as gaseous feedstock and single carbon nanotubes as deposition substrates. Aside the cones, micrometer-sized carbon beads or fibre segments are deposited meanwhile which are a key morphological component for allowing handling and mounting the carbon cones and then using them for various applications. Based on both the literature dealing with pyrolytic carbon deposition processes and experimental observations, a peculiar deposition mechanism is proposed, involving the transient formation of pitch-like liquid phase droplets which deposit onto the individual carbon nanotubes. In this picture, it is believed that a key parameter is the diameter ratio for the droplets and the nanotubes, respectively. The cone concentric texture and perfect nanotexture are shown by high resolution transmission electron microscopy, which allows interesting mechanical and conducting properties to be predicted. Correspondingly, applications of the carbon nanocones as electron emitters for cold-field electron sources on the one hand, and as probes for various modes of near-field microscopy on the other hand, have been tested. [ABSTRACT FROM AUTHOR]

Epitaxial growth of III‐nitrides on 2D materials enables the realization of flexible optoelectronic devices for next‐generation wearable applications. Unfortunately, it is difficult to obtain high‐quality III‐nitride epilayers on 2D materials such as hexagonal BN (h‐BN) due to different atom hybridizations. Here, the epitaxy of single‐crystalline GaN films on the chemically activated h‐BN/Al2O3 substrates is reported, paying attention to interface atomic configuration. It is found that chemical‐activated h‐BN provides BON and NO bonds, where the latter ones act as effective artificial dangling bonds for following GaN nucleation, leading to Ga‐polar GaN films with a flat surface. The h‐BN is also found to be effective in modifying the compressive strain in GaN film and thus improves indium incorporation during the growth of InGaN quantum wells, resulting in the achievement of pure green light‐emitting diodes. This work provides an effective way for III‐nitrides epitaxy on h‐BN and a possible route to overcome the epitaxial bottleneck of high indium content III‐nitride light‐emitting devices. [ABSTRACT FROM AUTHOR]

Herein, preparation of Ag2ZnSnSe4 (AZTSe) thin films using physical vapor deposition followed by selenization in a quartz tube with rapid thermal process (RTP) is reported. The precursor stacks, [Sn/Se/ZnSe/Se/Ag/Se] × 4, are deposited onto the glass substrate at 100 °C using the combination of thermal and e‐beam evaporation methods. The post selenization of precursors is conducted at different temperatures (300–425 °C). The X‐ray diffraction and Raman spectra of the precursor films selenized at 400 °C reveal the formation of single‐phase AZTSe, exhibiting a kesterite structure with a preferred orientation along the (112) plane. These films show larger grains of ≈230 nm with the homogeneous distribution of Ag, Zn, Sn, and Se across the film thickness. The precursor films selenized at temperatures ≤400 °C show the fundamental absorption edge of AZTSe (Eg = 1.36–1.44 eV) as well as an additional adsorption edge (Eadd = 1.31–1.32 eV) corresponding to ZnSn + SnZn defect complex. The Hall effect measurement indicates n‐type conductivity irrespective of selenization temperature. For films selenized at 400 °C, the carrier concentration is decreased to 2.83 × 1011 cm−3 and results in a high mobility of 73.9 cm2(V s)−1, which is attributed to the reduction of SnZn defects. [ABSTRACT FROM AUTHOR]

• Siderite growth kinetics as a function of supersaturation. • Chemical affinity-based rate laws. • Comparison between Ca- and Fe(II)-carbonate systems. The widespread occurrence of siderite at the Earth's surface has motivated investigations into the thermodynamic factors controlling its stability for most of the last century. However, despite a new appreciation for multiple Fe(II)-carbonate mineralisation pathways, the rates of siderite growth have not been accurately predicted as a function of solution chemistry. This has impeded a quantitative understanding of myriad geochemical systems, both modern and ancient. To address this issue, we investigated the growth kinetics of synthetic siderite seeds in anoxic closed-system conditions at 298.15 K and 1 bar. On the basis of monitoring the chemical evolution of the bulk solutions over the course of 46 days, our results demonstrate two distinct relationships between kinetic behaviour and solution saturation (Ω) with respect to siderite. These relationships are best explained by chemical affinity-based rate laws that have been extensively applied to the growth kinetics of calcite (a mineral isostructural with siderite). More specifically, the surface area-normalised siderite growth rates (mol · m−2 · s−1) display a linear correlation with supersaturation (Ω - 1) when Ω ≳ 5 , suggesting a growth rate controlled by the transport of ions to the mineral surface ( r tr ): r tr = 10 - 12.60 ± 0.16 (Ω - 1) 1.057 ± 0.112. At low solution saturation, growth rates are consistent with spiral mechanism-dominated surface reactions ( r sr ), exhibiting a parabolic correlation with (Ω - 1): r sr = 10 - 13.42 ± 0.14 (Ω - 1) 1.868 ± 0.307. These data show that at comparable solution saturation at 25 °C, siderite growth is nearly 7-orders of magnitude slower than that of calcite. These kinetic behaviours imply that most examples of natural Fe(II) supply fluxes (e.g., dissimilatory iron reduction, hydrothermal activity, or dissolution of other Fe(II)-minerals) would only be balanced by siderite precipitation rates at very high supersaturation, or, if the barrier to Fe(II)-carbonate nucleation is surpassed, balanced by episodic fluctuations in precipitation rate in response to Fe(II) accumulation. In combination with kinetic barriers influencing nucleation, this slow growth rate provides a straightforward explanation for the common observation that many anoxic water bodies are persistently supersaturated with respect to siderite, and implies that the precipitation of siderite may be more dynamic than previously appreciated. [ABSTRACT FROM AUTHOR]

Due to the unique bandgap tunability of bilayer graphene, the preparation of large‐sized bilayer graphene has attracted a wide range of attention. Herein, the preparation of bilayer graphene, from stacking order to growth mechanism, is reviewed, and the chemical vapor deposition (CVD) of AB‐stacked bilayer graphene on copper substrate is emphasized. Various methods and growth strategies to synthesize bilayer graphene and the corresponding growth mechanisms are discussed. Mechanisms of layer‐by‐layer growth, the hydrogen passivation of graphene edges for the formation of bilayers, and carbon atoms penetrating through a copper wall for bilayer growth are included and highlighted for a better understanding of controlling bilayer graphene uniformity and forming its stacking order. Finally, the remaining challenges and the potential development of CVD‐controlled growth of bilayer graphene are outlined. [ABSTRACT FROM AUTHOR]

Producing high-quality two-dimensional (2D) covalent organic frameworks (COFs) is crucial for industrial applications. However, this remains significantly challenging with current synthetic techniques. A deep understanding of the intermolecular interactions, reaction temperature, and oligomers is essential to facilitate the growth of highly crystalline COF films. Herein, molecular dynamics simulations were employed to explore the growth of 2D COFs from monomer assemblies on graphene. Our results showed that chain growth reactions dominated the COF surface growth and that van der Waals (vdW) interactions were important in enhancing the crystallinity through monomer preorganization. Moreover, appropriately tuning the reaction temperature improved the COF crystallinity and minimized the effects of amorphous oligomers. Additionally, the strength of the interface between the COF and the graphene substrate indicated that the adhesion force was proportional to the crystallinity of the COF. This work reveals the mechanisms for nucleation and growth of COFs on surfaces and provides theoretical guidance for fabricating high-quality 2D polymer-based crystalline nanomaterials.

Abstract This work investigates the metal induced crystallization of hydrogenated amorphous Silicon (a-Si:H) thin films, processed by plasma enhanced chemical vapor deposition, using Au nanoparticles (AuNPs) as crystallizing mediator metal. Electrophoresis deposition (EPD) of colloidal AuNPs was used to coat the Si substrates before the a-Si:H processing. Then, the crystallization was conducted by isothermal annealing for temperatures above the eutectic (500 and 600 °C). Raman spectroscopy analysis showed that the crystalline volume fraction doubled as the EPD time increases. Scanning electronic microscopy and energy-dispersive X-ray microanalysis revealed that AuNPs induced crystallization at 600 °C was achieved through eutectic reaction with mixing layers. Structural characterizations showed that the low amounts of AuNPs exhibited a metal mediating effect more pronounced than that of continuous Au thin film deposited by dry physical methods. The enhancing effect of AuNPs was assigned to their size dependent high surface energy. Herein, we discuss as well, the effect of the EPD time on the development of Si crystallites on the basis of thermodynamic and kinetic considerations. [ABSTRACT FROM AUTHOR]

A detailed understanding of gelation mechanism can enable the properties of gels to be tuned for various applications, and may possibly help in understanding the aggregation of different biomolecules. We report a detailed study of the morphological and physio-chemical changes, dynamics (of a probe), and kinetics during the gelation of europium and calcium cholate hydrogels, leading to the development of a growth model. AFM images showed the transition of aggregated particles (100–150 nm) in the sol phase growing to a fibrous network in the gel through the entanglement of fibres, and not by dendritic growth (height analysis). The dynamic changes during this phase transformation were studied using a fluorescence probe (change in intensity and lifetime). We have been able to delineate the growth mechanism by using a combination of Eu (III) luminescence and a polarity sensitive fluorescence probe. The growth was found to follow the nucleation–elongation model, and these two phases responded in distinctly different fashions in rheological and luminescence measurements. [ABSTRACT FROM AUTHOR]

Abstract Kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) shows great promise in thin film photovoltaic application due to its reasonable band gap, low cost and non-toxic earth-abundant composition. Post-selenization is the generally adopted approach to obtain CZTSSe film with large-grain size. Thoroughly understanding and well controlling the grain growth process during selenization is thus essential for achieving high-performance solar cell devices. Here we demonstrate that the absorber microstructure can be adjusted by altering selenization conditions, especially the heating rate and annealing time. It is found that heating rate determines formation manner of top CZTSSe layer, while annealing time affects both the crystallization degree of bottom CZTSSe layer and the selenization of Mo contact layer. Properly adjusting the annealing time at an optimized heating rate is proven to successfully eliminate the fine-grain layer and obtain high quality CZTSSe thin films with large-size grains. Based on the observations, growth mechanisms for the microstructure development during selenization of solution processed Cu 2 ZnSnS 4 films are suggested. Finally, CZTSSe device efficiency of 9.24% is achieved at an optimal selenization condition. Highlights • The growth mechanisms of the solution processed Cu 2 ZnSn(S,Se) 4 thin films are suggested. • The bottom fine-grain layer and the thickness of MoSe 2 can successfully adjust by changing the selenization conditions. • The PCE of CZTSSe solar cells is significantly enhanced from 7.06% to 9.24% by optimizing the selenization conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • ZIF-8 films were grown for the first time on CVD deposited amorphous Si layers. • The role of solvents and surface chemistry on the growth process was studied. • The silanol density and the Lewis basic strength of the surfaces affect the relevant reaction steps. • Experimental results were validated by the DFT modelling of the proton exchange. Abstract Thin amorphous silicon films, deposited at low temperature by Inductively Coupled Plasma Chemical Vapor Deposition, have, for the first time, been employed as substrate for ZIF-8 growth. In order to investigate the role of the surface chemistry on the nucleation process, films have also been grown on other silicon-based substrates such as H-terminated Si(1 0 0), SiO 2 and quartz. Film preparation was carried out at room temperature using a mixed Zn nitrate and imidazole solution in methanol or ethanol. Using methanol, continuous ZIF-8 films were obtained on amorphous Si and H-terminated Si(1 0 0), while less homogeneous films were formed on the other surfaces. In ethanol, slower growth rates occurred and thinner films, compared to the ones in methanol, were obtained. These slower rates highlight the different effects of the four surfaces on the growth process. These differences have been related to the silanol density of the surfaces and to the Lewis basic strength which affect imidazole moiety deprotonation. H-terminated Si(1 0 0) and amorphous Si turned out to be the most reactive surfaces, whereas on quartz and, especially, on SiO 2 reactivity was much lower. Experimental results have been validated by the DFT modelling of the proton exchange, which takes place between the imidazole group and the surface. Finally, the VOCs adsorption capability of ZIF-8 films grown on amorphous silicon has been evaluated through temperature desorption experiments. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is one of the main functional materials used to realize chemiresistive gas sensors. In addition, ZnO can be grown through many different methods obtaining the widest family of unique morphologies. However, the relationship between the ZnO morphologies and their gas sensing properties needs more detailed investigations, also with the aim to improve the sensor performances. In this work, seven nanoforms (such as leaves, bisphenoids, flowers, needles, etc.) were prepared through simple wet chemical synthesis. Morphological and structural characterizations were performed to figure out their growth mechanisms. Then, the obtained powders were deposited through screen-printing technique to realize thick film gas sensors. The gas sensing behavior was tested toward some traditional target gases and some volatile organic compounds (acetone, acetaldehyde, etc.) and compared with ZnO morphologies. Results showed a direct correlation between the sensors responses and the powders features (morphology and size), which depend on the specific synthesis process. The sensors can be divided in two behavioral classes, following the two main morphology kinds: aggregates of nanocrystals (leaves and bisphenoids), exhibiting best performances versus all tested gases and monocrystal based (stars, needle, long needles, flowers, and prisms).

Amid climate change and shifts in precipitation patterns, drought conditions are expanding worldwide. Drought stress severely threatens plant growth in arid and semi-arid regions, wherein shrubs play a crucial role in maintaining ecological stability. Despite its ecological significance, studies are lacking on how Nitraria sibirica adapts to long-term drought stress. Therefore, in this study, to elucidate the mechanism of drought stress adaptation in N. sibirica , we analysed morphological, physiological, and transcriptional characteristics of plants in two soil habitats: riparian (moist) and desert (arid). The results showed that in desert soils, as soil water content decreased, leaf thickness increased, while plant height and leaf area decreased. Physiologically, photosynthesis decreased; soluble sugar, starch, proline, and hydrogen peroxide content increased significantly; while soluble proteins decreased significantly. Additionally, membrane lipid peroxidation products and antioxidant enzyme activities significantly increased under drought stress. Then, Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis identified 313 key genes, which were considered the most significantly enriched in the photosynthesis and photosynthetic antenna protein pathways. Further, we found that the proteins encoding photosystem II (PsbP , PsbQ , PsbR , PsbY , and Psb27), photosystem I (PsaD , PsaF , PsaG , PsaH , PsaK , and PsaO), photosynthetic electron transport (PetF), and light-trapping antenna proteins were significantly downregulated under drought stress. Taken together, these results suggest that N. sibirica adapts to long-term drought conditions by suppressing photosynthesis, activating antioxidant systems, and recruiting osmoregulators. This study provides a basis for elucidating the growth mechanisms of N. sibirica under long-term drought stress conditions. [Display omitted] • Drought inhibits the growth of Nitraria sibirica. • Drought adaption was via suppressing photosynthesis. • Antioxidant activity increased in response to drought. • Transcription characteristics differed between the two habitats. • The genes impacted by drought were associated with photosynthesis. [ABSTRACT FROM AUTHOR]

The microstructural stability during aging at 750 °C of the γ/γ′ nickel-based superalloy AD730TM is investigated in this work. Strain-free aging and aging during fatigue tests are conducted, with a focus on the influence of the strain ratio, the maximum applied strain, and the cycle waveform (with or without dwell). Two classical mechanisms of γ′ precipitates aging are identified at 750 °C: the coarsening of small spherical γ′ precipitates via the thermally-activated Ostwald ripening process and the coalescence of at least two precipitates into one. These mechanisms appeared to be concomitant during aging. It has been demonstrated that the coarsening kinetics of γ′ precipitates can be described by a classical Lifshitz-Slyozow-Wagner (LSW) equation. The introduction of a cyclic strain during aging at 750 °C increases the coarsening kinetics by means of changes in the volume diffusion of γ′-forming elements and of constraint misfit effects. More precisely, it is shown that the higher the maximum applied strain and/or the strain rate, the higher the coarsening rates. Finally, dwell-fatigue promotes the activation of the γ′ coalescence at 750 °C.

Abstract Tantalum nitride (TaN) ultra-thin films deposited by Atomic Layer Deposition (ALD) are efficient diffusion barriers for copper interconnects embedded in silica matrix. The present paper reports a methodical investigation of the first stages of TaN ALD growth on either dense SiO 2 or nanoporous SiOCH surfaces. The deposited TaN x phases, film microstructure, chemistry and resistivity were characterized at different steps of ALD growth (from 0 to 160 ALD-cycles). While a granular morphology combining orthorhombic-Ta 3 N 5 (o-Ta 3 N 5) and cubic-TaN (c-TaN) was obtained on SiOCH, a continuous film mainly composed of o-Ta 3 N 5 was found when deposited on dense SiO 2. In both cases, TaN x films were not completely-crystallized. The electrical behavior is shown to be mainly driven by film morphology rather than by the intrinsic conductivity of the deposited phases. Growth modes on both surfaces are then discussed in terms of surface chemical reactivity: two growth timelines are proposed to explain the observed phenomena (film continuity, deposited phase, conductivity). As this methodical approach shows the major interest for a deposition on SiO 2 substrate, a surface functionalization of SiOCH has also been performed. It was determined that a 3 nm-thick SiO 2 layer capping the SiOCH surface is enough to recover the required properties for optimal TaN deposition. Highlights • Ultra-thin TaN films were deposited by ALD on SiO 2 and nanoporous SiOCH surfaces. • A granular morphology combining o-Ta 3 N 5 and c-TaN was obtained on SiOCH. • A continuous film mainly composed of o-Ta 3 N 5 was deposited on dense SiO 2. • Film resistivity is driven by morphology rather than by intrinsic phase conductivity. • A 3 nm-thick SiO 2 capping layer is enough to recover the required TaN properties. [ABSTRACT FROM AUTHOR]

Zinc Oxide is an important and multi-purpose material in various industries due to its particular chemical and physical properties. Discovering a cheap, fast, clean, safe, and easy to use method, to synthesize this oxide nanoparticle has attracted a lot of attention in recent applications. The unique properties of the microwave and its special heating capabilities have yielded desirable outcomes by combining different synthesis methods. In the recent years, the vast majority of studies focus on the microwave-assisted synthesis of zinc oxide nanoparticles. This review article attempts to go over the recent advancements on the synthesis of zinc oxide nanoparticles with the aid of microwave, different morphologies and applications obtained by this method. Various microwave-assisted synthesis methods are classified, including the solution-based methods such as hydrothermal, sol-gel, and combustion methods. Morphology of the nanoparticles can affect the properties, and subsequently, applications of these nanoparticles. On the other hand, there is great diversity of morphological and synthesis conditions of zinc oxide nanoparticles. Thus, categorizing the synthesis techniques and providing features of them, facilitates the selection of appropriate method for designing new hierarchical structures with potential properties for future applications. Also it is endeavored to focus on the formation mechanisms of these methods. Finally, the various morphologies obtained under microwave radiation and their formation mechanisms are discussed and the effective factors in the synthesis are analyzed and presented. The potential and suitable fields of development and progress in the future studies are also proposed. [ABSTRACT FROM AUTHOR]