Optical and TEM characterization of phase transformation in Zn ion implanted and thermal oxidized quartz

The present work proposes a method for fabricating metallic zinc (Zn) nanoparticles in aqueous solution. An aqueous colloidal solution of metallic Zn nanoparticles was prepared from Zn acetate by electrolysis under ultrasonic irradiation in water. Transmission electron microscopy and X-ray diffractometry revealed that metallic Zn nanoparticles with a crystal structure of hexagonal and a particle size of ca. 130 nm were produced using carbon bars as electrodes. However, the carbon that peeled off with the ultrasonic irradiation was included in the nanoparticles. High-purity metallic Zn nanoparticles with sizes of 30–90 nm could be fabricated using metallic Zn plates as the electrodes. The metallic Zn nanoparticles were chemically stable in both aqueous solution and the atmosphere. The chemically-stable metallic Zn nanoparticles are expected to be applied to catalyst, fabrication of alloy nanoparticles composed of Zn and other metals, anti-rust paint, etc.

<p style="text-align:justify; margin-bottom:11px"><span style="font-size:11pt"><span style="line-height:200%"><span style="font-family:Calibri,"sans-serif""><span lang="EN-US" style="font-size:12.0pt"><span style="line-height:200%"><span style="font-family:"Times New Roman","serif"">Fibrous plants are renewable resources that are abundant in nature. Economically and ecologically, it is especially advantageous to create high-performance composites using inexpensive natural fibres like water hyacinth (Eichhornea crassipes). As a composite matrix, remarkable thermosetting resins like polyester are frequently utilized because polymer composites have excellent dimensional stability, thermal stability, and mechanical qualities. For this investigation, hot curing and solution impregnation procedures were used to create several composites from water hyacinth fibre and polymer. This study's objective is to ascertain how the textures alter when PVC and bio composite components are included. This research is being done to find out what changes polymer materials with fiber-reinforced nanoparticles make. This study uses the water hyacinth (Eichornia crassipers) as a bio-composite material. This type of water hyacinth is usually only seen when the rivers are overflowing. The crystallinity index of water hyacinth fibre composite is 54.82%. The outside of the hyacinth composite is examined under a transmission electron microscope. Hyacinth fibre composite heat degradation is measured using the thermo gravimetric research technique. Additionally the result of this study is to find mechanical, chemical resistance, and morphological properties.</span></span></span></span></span></span></p>

SummaryAlthough it has been shown that configurational entropy can improve the structural stability in transition metal oxides (TMOs), little is known about the oxidation state of transition metals under random mixing of alloys. Such information is essential in understanding the chemical reactivity and properties of TMOs stabilized by configurational entropy. Herein, utilizing electron energy loss spectroscopy (EELS) technique in an aberration-corrected scanning transmission electron microscope (STEM), we systematically studied the oxidation state of binary (Mn, Fe)3O4, ternary (Mn, Fe, Ni)3O4, and quinary (Mn, Fe, Ni, Cu, Zn)3O4 solid solution polyelemental transition metal oxides (SSP-TMOs) nanoparticles. Our findings show that the random mixing of multiple elements in the form of solid solution phase not only promotes the entropy stabilization but also results in stable oxidation state in transition metals spanning from binary to quinary transition metal oxide nanoparticles.

This study assesses the antimicrobial, antibiofilm, and antiurease properties of selenium (Se), zinc (Zn), and zinc selenide (ZnSe) nanoparticles (NPs) against clinically pathogenic strains of Streptococcus salivarius and Proteus mirabilis. The Se, Zn, and ZnSe NPs, synthesized by Pseudomonas aeruginosa OG1, were characterized using transmission electron microscopy (TEM) revealing average sizes of approximately 30 ± 10 nm, 30 ± 15 nm, and 40 ± 10 nm, respectively. Atomic force microscopy (AFM) was used to examine the morphological and topological characteristics of the NPs. The structural and crystal characteristics were investigated using X-ray diffraction (XRD). Among the evaluated NPs, Zn NPs at a concentration of 200 mg/mL exhibited the most substantial growth inhibition zone against S. salivarius. Conversely, the highest antibiofilm activity was observed against P. mirabilis, notably with 200 µg/mL Zn NPs. In the context of antiurease activity, both 100 μg Zn and ZnSe NPs caused complete urease inhibition (100%) in P. mirabilis within the initial 5 h, with notable inhibition rates of 94% and 80%, respectively, observed against S. salivarius. Significantly, in the current landscape of NP research primarily focused on antimicrobial and antibiofilm properties, our study stands out due to its pioneering exploration of antiurease activities with these NPs. This distinctive emphasis on antiurease effects contributes original and unique value to our study, offering novel insights into the broader spectrum of NP applications, and paving the way for potential therapeutic advancements.

Highly Efficient AuPd Catalyst for Synthesizing Polybenzoxazole with Controlled Polymerization

Self‐organization of metallic nanoparticles (NPs) has recently been reported upon visible continuous‐wave (cw) laser exposure [1]. The self‐organized structures are Ag NP gratings embedded in a thin TiO 2 film deposited on glass. Such composite structures exhibit singular visual effects that can find applications in secured traceability. The related optical properties directly depend on the NP size distribution, the average grating period, the organization rate and the TiO 2 thickness and refractive index. These sample features appear to be largely controlled by the temperature rise that occurs during the laser‐induced self‐organization process. The aim of the present contribution is to estimate the plasmon‐induced temperature rise which appears to be strongly influenced by the laser scanning speed. To do so, Raman microspectroscopy and various modes of transmission electron microscopy (TEM) are used. The latter allow accurate information to be acquired on the NP size distributions resulting from different temperature rises, on their localization in the film and on the phase and chemical changes that occur in the film and the substrate surrounding NPs. Finally, we show how such thermal effects can be considerably decreased when using femtosecond (fs) laser pulses to initiate the NP self‐organization. The TiO 2 thin layer used in this work is initially mesoporous and amorphous and contains small silver NP of 1‐3 nm as described in a previously published article [1]. The self‐organized growth of silver NPs is implemented by scanning a laser beam focused on the sample surface at a constant speed. Post mortem Raman microspectroscopy shows that TiO 2 remains amorphous or adopt successively anatase, both anatase and rutile or only rutile crystalline forms for increasing laser scanning speeds, which was confirmed by high resolution TEM micrographs. Further in situ Raman microspectrocopy characterizations also attest an increase in temperature from 200°C to 750°C from low speed to higher speed in a range where anatase is formed; This increase of the temperature when the scanning speed increases was totally unexpected. In addition to TEM crystallographic characterization, scanning electron microscopy (SEM) appeared to be useful to identify different morphologies for anatase and rutile nanocrystals and to study changes in the nanocrystal density as a function of speed. Scanning TEM (STEM) micrographs and electron energy loss spectroscopy (EELS) analysis of sample cross‐sections prepared by focused ion beam (FIB) give further interesting information about the in‐depth structure of samples. Ag nanoparticles are located below the TiO 2 film (Fig. 1a) made of TiO 2 nanocrystals immersed in a Si‐based amorphous phase, in a new interfacial thin amorphous layer mixing both Ti from the initial film and Si from the glass substrate (Fig. 1b). A three‐dimensional reconstruction of the film sample from a series of FIB‐SEM experiments confirms that all Ag NPs are rather spherical and located in a single plane just below the nanocrystalized TiO 2 layer. High angle annular dark field scanning TEM (HAADF STEM) imaging was used to study systematically non‐monotonous changes in the NP size distribution with the temperature rise for many samples. All studies that we have performed so far point out that the temperature rise can be considered as a drawback since it affects the integrity of the supporting material; we present here few results obtained with fs laser pulses in order to investigate a way to self‐organize metallic NPs without high temperature rise in order to preserve the substrate and give the ability to work on softer substrates like plastic ones. Self‐organization can successfully be obtained without altering the substrate top surface (Fig. 1 c‐d). Ag NPs remain localized in the TiO 2 films, which is only locally crystallized around the grown NPs, as attested by STEM‐diffraction maps recorded in TEM. To conclude, this paper demonstrates the interest of a multimodal application of TEM techniques in order to provide a thorough study of the 3D nanostructure and chemical composition of complex samples made of Ag NP gratings embedded in a nanocrystallized TiO 2 film, which result from laser‐induced self‐organization processes. It provides crucial information on thermal effects that drive the laser‐induced self‐organization process.

A Magnetocatalytic Propelled Cobalt–Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

The results of the synthesis of metallic zinc nanoparticles (NPs) and its oxide in amorphous quartz, implanted with 64Zn+ ions with an energy of 50 keV and a dose of 5 × 1016/cm2, and isochronously annealed in oxygen with a step of 100°C for 1 hour at each step in the temperature range of 400−900°C, are presented. For the study we use the methods of electron scanning and transmission microscopy in combination with energy-dispersive spectroscopy and electron diffraction, as well as atomic-force microscopy, optical transmission and photoluminescence. It is found that after implantation, a few Zn-containing NPs with a size of less than 100 nm are recorded on the quartz surface, and metal Zn NPs with a size of about 3 nm are recorded inside the sample body. It is established that during annealing, the implanted sample becomes more transparent as a constant transition from the opaque phase of metallic Zn to the transparent phases of its oxide and silicide occurs. After annealing at 700°C, the quartz surface becomes very developed and numerous Zn-containing NPs and craters are recorded on it; zinc-oxide nanoparticles with a size of 4.5 nm are formed in the sample body. In this case, a photoluminescence peak in the form of a doublet at a wavelength of 370 nm, caused by the ZnO phase, is formed on the spectrum. After annealing at 900°C, the zinc-oxide phase degrades and a willemite phase of Zn2SiO4 is formed.

Janus nanoparticles are nanoparticles (NPs) displaying two sides of different chemical nature which makes them of high interest. The formation of the Janus shell provides the NPs an amphiphilic character, which can therefore self‐assemble in a tunable fashion by varying different experimental parameters such as size, polymer ratio and temperature. Here, Au NPs coated by polyethylene glycol (PEG) and both polystyrene (PS) and poly(N‐isopropylacrylamide) (PNIPAM) were investigated. [1] The true Janus character of the NPs was determined by electron tomography. Characterization of polymer coated particles by electron microscopy is challenging due to the low contrast of the organic materials. The goal was to distinguish the two different polymers in two types of particles (PEG+PNIPAM and PEG+PS coated Au NPs). Different approaches were used to improve the contrast between the two polymers. The PEG+PNIPAM particles were characterized by specific staining of the hemispheres while the character of the PEG+PS particles was investigated by the growth of silica. First, the PEG+PNIPAM coated NPs were stained with 3 mM CuSO 4 .5H 2 O solution to generate sufficient contrast in the Transmission Electron Microscope (TEM). PNIPAM‐coated NPs showed damage of the polymer upon electron beam irradiation. For PEG‐coated NPs a stable shell was observed. In an attempt to distinguish PNIPAM and PEG, PEG+PNIPAM coated particles were stained and investigated with TEM (Fig. 1). Since conventional TEM images are 2D projections from a 3D object, electron tomography was performed. It must be noted that the conventional technique for tomography in materials science, high angle annular dark field scanning TEM (HAADF‐STEM), could not be applied due to the large difference in atomic number Z for Au and the elements in the polymer shell. Instead, Bright‐Field TEM tomography was applied. Images were acquired over the largest possible range (‐76° to +76°) every 2°, aligned and reconstructed by the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm in the Astra Toolbox. [2] The obtained 3D reconstruction displayed rather low contrast between the shell and the background. Manual segmentation based on the orthoslices (xy‐, yx‐ and zx‐direction) could be carried out. This method provided a 3D reconstruction that clearly confirms the formation of stained half‐shells (Fig. 3). In the second case of PEG+PS coated Au NPs, an attempt of staining with calcium phosphate was carried out. In TEM images hemispheres could be observed, but selective staining could not be confirmed. Due to the high affinity of PEG by silica, PEG is able to act as a primer to promote silica condensation. Since PS is hydrophobic and does not allow silica nucleation, the silica shell was expected to occur only at the parts of the NPs that are coated by PEG (Fig. 2). Either staining or silica shell growth over PEG‐coated areas resulted in the observation of semi‐shells (Janus character) in Au NPs by TEM and electron tomography.

Durability is still one of the main aspects for which significant progress is expected to allow a larger deployment of fuel cell vehicles. It is therefore crucial to further study the degradation mechanisms of the MEA components and to quantify them in relation to the fuel cell operation conditions. The different electron microscopy techniques (Fig. 1), including scanning electron microscopy (SEM) and transmission electron microscopy (TEM), have shown their essential contribution to offer deep insight into several degradation mechanisms and will likely continue to have an impact on future efforts to improve durability.TEM has been widely used to characterize Pt based PEMFC electro-catalysts and provides information on the size distribution of nanoparticles (NPs), their morphology and crystallographic structure. In addition, microscopes equipped with a Cs probe corrector and associated with electron energy loss spectroscopy (EELS) or X-ray energy dispersion spectroscopy (EDS) allow analyzing the chemical composition of each atomic column. Therefore, TEM characterization has been widely used to develop new high-performance catalysts with well-controlled chemistry/morphology and to study their stability.The main Pt NP degradation mechanism that occurs during fuel cell operation is the electrochemical Ostwald ripening leading to a decrease in the number of NPs smaller than 4 nm associated with an increase in the average NP size (usually from 2-3 nm to 4-5 nm). If the cathode potential becomes higher than 0.9 - 1V, the greater dissolution of the small NPs produces a large amount of Pt ions that migrate toward the membrane where they are reduced by the H2 crossing over to form membrane Pt precipitates. Similar results are observed for Pt alloy NPs but in this case, the electrochemical Ostwald ripening mechanism leads to an increase in the thickness of the Pt shell surrounding the alloy core (typically from 0.6 to 1 nm)1 that affects their activity. Indeed, the negative standard potential of the non-noble elements (Co, Ni...) prevents the reduction of their ions within the MEA and only Pt is redeposited on the larger NPs. Ions of the non-noble elements migrate into the electrolyte and lower its proton conductivity. The membrane contamination can be detected by SEM/EDS analyses performed on MEA cross-section but taking care during sample preparation to prevent altering the ions distribution. This contamination can be limited by avoiding using Pt alloy NPs smaller than 4 nm. .More recently, electron tomography analyses have revealed that when high surface area carbon are used, many Pt NPs are located inside the carbon and that during ageing tests, these interior NPs are less affected by the coarsening mechanism2,3. It is assumed that the confinement of the NPs inside small pores increases their interspacing and thus hampering the electrochemical Ostwald ripening mechanism. The development of carbon support with a well-controlled porosity allowing an optimal NP confinement seems to be a very promising research direction for which electron tomographic analyses will be essential.On the other hand, the carbon support must have a high oxidation resistance to prevent structural collapse of the porous cathode catalyst layer if high potential values are accidentally reached as can locally happen during the start-up/shut-down phases. This severe cathode degradation by carbon corrosion is highlighted on MEA cross-section SEM images. Today FIB-SEM analyses providing 3D images of the porous structure offer the possibility to go further by measuring the evolution of the porosity.Ionomer is also an important MEA component whose degradation dramatically limits PEMFC durability. MEA cross-section SEM images can reveal the physical degradation of the membrane such as thinning. In the electrode, however, the study of ionomer degradation remains challenging because high resolution 3D images are required. For this purpose, electron tomography experiments are still under development.Many degradation studies used to concern MEA aged during accelerated stress test specific for each component. In our laboratory, we are more focused on identifying degradation phenomena that occur in stacks operating in or near real-world conditions. For these studies, we couple electron microscopy analyses with in-situ local measurements using segmented devices to select the regions of interest and to relate local degradation to local performance and conditions1. Acknowledgement : this project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation program under grant agreement No. 779565 (ID-Fast) and previously No. 621216 (SecondAct).

Void formation in silica glass induced by thermal oxidation after Zn + ion implantation

Background: Propagation of pathogens has considered an important health care problem due to their resistance against conventional antibiotics. The recent challenge involves the design of functional alternatives such as nanomaterials, used as antibacterial agents. Early stages of antibacterial damage caused by metallic nanoparticles (NPs) were studied by Transmission Electron Microscopy (TEM) and combined Scanning Transmission Electron Microscopy with High Angle Annular Dark Field (STEM-HAADF), aiming to contribute to the elucidation of the primary antibacterial mechanism of metallic NPs.Methods: We analyze the NPs morphology by TEM and their antibacterial activity (AA) with different amounts of Ag and Cu NPs. Cultured P. aeruginosa were interacted with both NPs and processed by TEM imaging to determine NPs adhesion into bacteria wall. Samples were analyzed by combined STEM-HAADF to determine the NPs penetration into bacterium and elemental mapping were done.Results: Both NPs displays AA depending on NPs concentration. TEM images show NPs adhesion on bacterial cells, which produces morphological changes in the structure of the bacteria. STEM-HAADF also proves the NPs adhesion and penetration by intracellular localization, detecting Ag/Cu species analyzed by elemental mapping. Moreover, the relative amount of phosphorus (P) and sulfur (S) increases slightly in P. aeruginosa with the presence of NPs. These elements are associated with damaged proteins of the outer cell membrane.Conclusions: Combined microscopy analyses suggest that the early stages of antibacterial damage caused by alteration of bacterial cell wall, and can be considered a powerful tool aiming to understand the primary antibacterial mechanism of NPs.

The use of nanotechnologies in agriculture is an advanced course enabling to reduce the dependence of crop tonnage and quality on external factors. A special section is represented by studies of pre-sowing treatment of seeds with metal nanoparticles (NPs). In this work, it is shown for the first time that pre-sowing treatment of seeds with metal nanoparticles with specific physicochemical parameters affects morphometric indices of the of winter wheat growth at all stages of its development as well as the plant resistance to pathogens, grain quality, the degree of its damage from fusarium and elemental composition of the soil after harvesting. Effects depend on the type of metal used. Our aims were to study i) effects of pre-sowing seed treatment with iron, zinc, and copper NPs on the growth parameters and grain quality of winter wheat, and ii) whether this treatment affects the soil after harvest. Iron, zinc, and copper NPs were obtained by the method of high temperature condensation at the Migen-3 apparatus (Institute of Energy Problems of Chemical Physics RAS, Russia). The shape and size of NPs were evaluated by JSM-7401F scanning electron microscope (JEOL Ltd., Japan). X-ray phase analysis was carried out using an ADP-1 X-ray analyzer (NPO Modern Technologies of Non-Destructive Control, Russia). Field trials were carried out at the validation test site of the Novokuban Branch of the Rosinformagrotech (Krasnodar Territory). The predominant soil type is typical chernozem, with medium humus content, heavy loamy. The sowing of winter wheat (Triticum aestivum L.) cv. Stan was performed on October 4, 2016 with a setting seed rate 240 kg/h. The assigned treatments were as follows: control (seeds without treatment), seed treatment with Fe NPs (5×10-4 %), Zn NPs (1×10-4 %), Cu NPs (5×10-7 %); Fe NPs + Zn NPs + Cu NPs (5×10-4 % + 1×10-4 % + 5×10-7 %). Soil samples were collected for chemical analysis. For phenological and biometric observations, plants were taken from three locations of 1 m2 area from each experimental and control plot. Plant height, average root length, thickness of the main stem at the plant bottom, tillering and depth of the tillering node were measured. Iron, zinc, and copper NPs were round single-crystal structures covered with a semitransparent oxide film. Average diameter of Fe NPs was 27.0±0.51 nm, Zn NPs 54.0±2.8 nm, Cu NPs 79.0±1.24 nm. X-ray phase analysis showed that iron NPs consisted of 53.6 % crystalline metal phase, Fe3O4 content was 46.4 %, and the oxide film thickness was 3.5 nm. Cu and Zn NPs contained only crystalline metal phases with the similar oxide film thickness, 0.5 to 1.0 nm. Pre-sowing treatment of seeds with Fe NPs affected the height of seedlings, promoted the formation of a developed root system with total root length being 4.5 % more (р ≤ 0.05) than in the control group, and increased the seedling stand density by 9.96 % (р ≤ 0.05) vs. control. Pre-harvest monitoring of crops revealed an increase in the yield of wheat plant mass after pre-sowing seed treatment with Fe and Cu NPs. Stem length was larger than that of the control (81.3±1.2 sm) by 3.8 and 8 cm, respectively, the average thickness of the main stem at the plant bottom being larger by 6 mm (when processing with Fe NPs) and 5 mm (when treating with Cu NPs) in comparison with the control (44 mm). Plant stands productivity enhancement after Fe and Zn NPs treatments, higher resistance to pathogens (by 3.85 times vs. control) under Fe NPs, a tendency to an increase in the average 1000-grain weight when using NPs of Fe, Zn, and Cu were observed. The crop quality parameters had higher values as compared to the control: in terms of the content of wet gluten by 6.12 % when seeds were treated with Zn and Cu NPs or with NPs composition; the protein mass fraction was larger under treatment with Cu NPs and the NPs composition by 5.1 % vs. control. Pre-sowing treatment with Fe and Zn NPs reduced the prevalence of Fusarium infection in grain by 1.24 and 2.25 times respectively vs. control. Elemental analysis of the soil after harvesting showed a decrease in the content of mobile forms of phosphorus by 27 % and zinc by 48 % after seed treatment with Zn NPs in comparison with the control, and a decrease in the phosphorus mobile forms by 23 % and sulfur by 7 % after pre-sowing treatment with Cu NPs in comparison with the control. The data obtained demonstrate the effective influence of the pre-sowing treatment of seeds by metal NPs on the growth, development and grain quality of wheat.

The use of nanotechnologies in agriculture is an advanced course enabling to reduce the dependence of crop tonnage and quality on external factors. A special section is represented by studies of pre-sowing treatment of seeds with metal nanoparticles (NPs). In this work, it is shown for the first time that pre-sowing treatment of seeds with metal nanoparticles with specific physicochemical parameters affects morphometric indices of the of winter wheat growth at all stages of its development as well as the plant resistance to pathogens, grain quality, the degree of its damage from fusarium and elemental composition of the soil after harvesting. Effects depend on the type of metal used. Our aims were to study i) effects of pre-sowing seed treatment with iron, zinc, and copper NPs on the growth parameters and grain quality of winter wheat, and ii) whether this treatment affects the soil after harvest. Iron, zinc, and copper NPs were obtained by the method of high temperature condensation at the Migen-3 apparatus (Institute of Energy Problems of Chemical Physics RAS, Russia). The shape and size of NPs were evaluated by JSM-7401F scanning electron microscope (JEOL Ltd., Japan). X-ray phase analysis was carried out using an ADP-1 X-ray analyzer (NPO Modern Technologies of Non-Destructive Control, Russia). Field trials were carried out at the validation test site of the Novokuban Branch of the Rosinformagrotech (Krasnodar Territory). The predominant soil type is typical chernozem, with medium humus content, heavy loamy. The sowing of winter wheat (Triticum aestivum L.) cv. Stan was performed on October 4, 2016 with a setting seed rate 240 kg/h. The assigned treatments were as follows: control (seeds without treatment), seed treatment with Fe NPs (5×10-4 %), Zn NPs (1×10-4 %), Cu NPs (5×10-7 %); Fe NPs + Zn NPs + Cu NPs (5×10-4 % + 1×10-4 % + 5×10-7 %). Soil samples were collected for chemical analysis. For phenological and biometric observations, plants were taken from three locations of 1 m2 area from each experimental and control plot. Plant height, average root length, thickness of the main stem at the plant bottom, tillering and depth of the tillering node were measured. Iron, zinc, and copper NPs were round single-crystal structures covered with a semitransparent oxide film. Average diameter of Fe NPs was 27.0±0.51 nm, Zn NPs 54.0±2.8 nm, Cu NPs 79.0±1.24 nm. X-ray phase analysis showed that iron NPs consisted of 53.6 % crystalline metal phase, Fe3O4 content was 46.4 %, and the oxide film thickness was 3.5 nm. Cu and Zn NPs contained only crystalline metal phases with the similar oxide film thickness, 0.5 to 1.0 nm. Pre-sowing treatment of seeds with Fe NPs affected the height of seedlings, promoted the formation of a developed root system with total root length being 4.5 % more (р ≤ 0.05) than in the control group, and increased the seedling stand density by 9.96 % (р ≤ 0.05) vs. control. Pre-harvest monitoring of crops revealed an increase in the yield of wheat plant mass after pre-sowing seed treatment with Fe and Cu NPs. Stem length was larger than that of the control (81.3±1.2 sm) by 3.8 and 8 cm, respectively, the average thickness of the main stem at the plant bottom being larger by 6 mm (when processing with Fe NPs) and 5 mm (when treating with Cu NPs) in comparison with the control (44 mm). Plant stands productivity enhancement after Fe and Zn NPs treatments, higher resistance to pathogens (by 3.85 times vs. control) under Fe NPs, a tendency to an increase in the average 1000-grain weight when using NPs of Fe, Zn, and Cu were observed. The crop quality parameters had higher values as compared to the control: in terms of the content of wet gluten by 6.12 % when seeds were treated with Zn and Cu NPs or with NPs composition; the protein mass fraction was larger under treatment with Cu NPs and the NPs composition by 5.1 % vs. control. Pre-sowing treatment with Fe and Zn NPs reduced the prevalence of Fusarium infection in grain by 1.24 and 2.25 times respectively vs. control. Elemental analysis of the soil after harvesting showed a decrease in the content of mobile forms of phosphorus by 27 % and zinc by 48 % after seed treatment with Zn NPs in comparison with the control, and a decrease in the phosphorus mobile forms by 23 % and sulfur by 7 % after pre-sowing treatment with Cu NPs in comparison with the control. The data obtained demonstrate the effective influence of the pre-sowing treatment of seeds by metal NPs on the growth, development and grain quality of wheat.

The increase of coercivity and simultaneously reducing the amount of heavy rare earth elements of Nd‐Fe‐B magnets is of great economic and scientific interest. Both, the grain size of the hard magnetic Nd 2 Fe 14 B phase and the presence of a grain boundary (GB) phase and its chemical composition have a crucial influence on the coercivity of sintered Nd‐Fe‐B magnets [1], [2]. Besides the sinter processing also the production route of rapid solidification, also called melt‐spinning, for Nd‐Fe‐B magnets satisfies the demand of the industry for magnets with high coercivity and energy product [3]. The variation of the process parameters has a significant influence on the microstructure, like grain size and occurring phases. Two isotropic Nd‐Fe‐B melt‐spun ribbons, ms‐A and ms‐B , with an average grain size of about 19 nm (STDV = 6 nm) ( ms‐B ) and 60 nm (STDV = 22 nm) ( ms‐A ) and a coercive field ranging from µ 0 H c = 0.6 T ( ms‐A ) to 1.0 T ( ms‐B ) were investigated in a nanoanalytical TEM/STEM study carried out on an analytical field emission transmission electron microscope (TEM) (FEI Tecnai F20) at 200 kV, which is equipped with a high angle annular dark field detector (HAADF), a silicon drift energy dispersive X‐ray detector (EDX) from EDAX and a Gatan Tridem GIF electron energy loss spectrometer (EELS). Conventional TEM sample preparation (cutting, thinning, ion milling) was conducted, in order to investigate large sample areas. For detailed nanoanalytical investigations Focused Ion Beam (FIB) samples were prepared in an FEI Quanta 200 3D DualBeam‐FIB using the lift‐out technique. A TEM bright field (BF) image shows the large grains of sample ms‐A (Fig.1a). Besides selected area electron diffraction (SAED) analysis (Fig1.b), the occurring phases were identified with Fast Fourier Transformation (FFT) (Fig.1c) of High Resolution (HR) TEM images (Fig.1d). The [100], [110] and [111] lattice fringes of the single crystalline (Pr,Nd) 2 (Fe,Co) 14 B phase (φ) are visible in Fig.1d. Beside the 2‐14‐1 phase two further Fe dominating phases Fe‐1 and Fe‐2 were found. Two single crystalline bcc‐Fe (α) grains of phase Fe‐1, which contains mostly Fe and small amounts of Co and O, are displayed in Fig.1d. This phase shows characteristic dotted morphology, were else the Fe‐2 phase has a homogeneous contrast like the Nd‐Fe‐B phase. Besides Fe also significant amounts of Nb and O were found in this phase. Large area EDX analysis have indicated about 40 % of the grains to be one of these two Fe phases and only 60 % are Nd‐Fe‐B grains and the ratio of the two Fe phases is approximately 50/50. The smaller grain size of sample ms‐B is observed in the TEM‐BF image (Fig.2a). The [001] lattice plains of an Nd‐Fe‐B grain was indexed with an FFT (Fig.2c) of the TEM Dark Field (DF) image (Fig.2d). An EELS line scan (ls) over an interface of two Nd‐Fe‐B grains shows no change in the chemical composition, implying that a grain boundary phase is not present in this material (Fig.3b,d). On the basis of the information on the microstructure obtained by this TEM study a numerical micromagnetic finite element model was created to simulate the influence of microstructural features like grain size and other occurring phases (Fig.3c). The micromagnetic simulation of the demagnetization curve of randomly oriented grains with direct intergranular coupling shows a decrease of the coercive field with increasing grain size (Fig.3a), which is in good agreement with the measured coercive field of the two samples.