Crystal Texture Research Articles

Time scales of olivine storage and transport as revealed by diffusion chronometry at Waitomokia Volcanic Complex, Auckland Volcanic Field, New Zealand

Detailed knowledge of the pre-eruptive time scales associated with magma storage and transport is vital to improve volcanic hazard forecasting in active volcanic regions. However, quantification of the timescales of volcanic processes at mafic volcanic centres in continental intraplate settings is challenging, despite them being a source of significant hazards for human populations and infrastructure due to their limited predictability in space and time. We conducted a detailed petrological study to investigate the time scales of olivine storage and transfer throughout the eruption sequence of Waitomokia Volcanic Complex, a tuff ring and scoria cone complex in the Auckland Volcanic Field. Olivine crystal textures and compositions were determined from stratigraphically-constrained samples of the volcanic complex, from the initial phreatomagmatic phase to the final magmatic phase. Olivine crystals are typically <300 μm in length and characterised by skeletal morphologies, displaying chemical zoning in forsterite (Fo = 100*Mg/[Mg + Fe]; mol%), CaO, MnO and NiO wt% contents. We classified olivine into three major groups based on their Fo core compositions: (1) normally zoned crystals with high Fo content (Fo > 85), (2) crystals with intermediate Fo contents (84–81), and (3) reversely zoned crystals with lower Fo core content (<80). Olivine chemical zoning (diffusion) profiles were modelled in the context of a specific magmatic environment linked with changes in thermodynamic variables during storage (temperature, pressure, and oxygen fugacity). We propose that the normally zoned olivine crystals grew in one magmatic environment (ME1), which subsequently intruded into a more evolved (lower MgO) environment (ME2), where they interacted and were stored for up to 135 days before their eruption. During magma ascent to the surface, a second magma mixing event occurred between ME2 and magma within a third magmatic environment (ME3), forming reversely-zoned olivine crystals yielding notably shorter ascent times of approximately a few days. The rocks from the opening phreatomagmatic phase of the eruption show a larger range in olivine group types compared to the final magmatic phase, where those from the deeper ME1 are more abundant. The short time scales of magma transport obtained in our study, on the order of days to months, should be informative of the warning times that may be encountered between the onset of volcanic unrest and an eruption in the Auckland Volcanic Field.

Friction and Wear of Hard Yet Tough TiN Coatings Deposited Using High-Power Impulse Magnetron Sputtering

The friction and wear response of hard coatings is complex, which largely depends on a good combination of hardness and toughness, and their service life is difficult to predict. Hence, in this work, hard yet tough TiN coatings were deposited using high-power impulse magnetron sputtering at 5–10 kW. With increasing sputtering power, the coatings showed a transition in crystal texture from (200) to (111), along with a refinement in microstructure, leading to an improvement in hardness (H) of 29.8–31.2 GPa and an effective Young’s modulus (E*) of 310–365 GPa. The hard yet tough TiN coatings deposited at 6.5 kW exhibited the highest H/E* and H3/E*2 ratios of 0.097 and 0.29, respectively, as well as the highest fracture toughness of 2.1 MPa·m1/2 and elastic recovery of 42.5%. Accordingly, the coatings possessed an enhanced adhesion and cohesion, in terms of micro-scratch critical load (LC3 = 19.67 N) and HF Rockwell HF1 level. The friction and wear response of hard yet tough TiN coatings under the normal load of 1–10 N were investigated to explore their durability and predict their critical load up to failure. Wear mechanisms changed from oxidative to severe abrasive wear, with load increasing from 1 to 10 N. At 2–5 N, a combination of oxidative and abrasive wear was observed. The coatings maintained their integrity up to the critical load of 9.4 N before failure event, with a maximum wear track depth of 1.8 μm, indicating their durability under the loading conditions.

Effect of N2 partial pressure on ZrN coating orientation and tribocorrosion behavior and mechanism

The ZrN coatings were prepared using multi-arc ion plating (MAIP) under different N2 partial pressures ranging from 10 % to 80 %. A comprehensive analysis of the microstructure, electrochemical behavior, and tribocorrosion properties of these coatings showed a gradual deposition rate decrease with rising N2 partial pressure. Analysis using GIXRD revealed higher N2 pressure led to a shift in crystal orientation from (111) to (200), initially increasing corrosion resistance but later declining. At 70 % N2 pressure, the ZrN coating exhibited the lowest values of capacitance Cpo (8.89 μF cm−2) and double-layer capacitance Cdl (1.14 × 10−7 F cm−2), with the highest values for the two-time constants τ recorded as 0.274 s and 5.749 s. The tribocorrosion behavior correlated closely with the corrosion performance, with the ZrN-70 % coating demonstrating superior tribocorrosion resistance and a minimal wear rate of 4.25 × 10−5 mm3/Nm. While the ZrN-80 % coating exhibited the lowest wear rate of 2.67 × 10−5 mm3/Nm, but was more susceptible to friction and corrosion synergy, causing localized failure. The outcomes reveal crystal texture significantly affected on the electrochemical and tribocorrosion characteristics of the coatings, primarily attributed to the robust passivation tendency and stability of the passivation film associated with the (200) crystal orientation. The dominant wear mechanism identified involves the interplay of adhesive, abrasive, and corrosion-erosion wear processes. Based on these results, ZrN coatings prepared using MAIP are expected to emerge as candidate materials for critical friction components in marine equipment or other corrosion-erosion environments.

Effect of temperature on the mechanical properties of Ni-based superalloys via molecular dynamics and crystal plasticity

Study on the influence of temperature on the mechanical properties across multiple scales has been a focus on the research of Hastelloy-X (HX) alloys for the application in high-temperature structure components. In this work, Molecular Dynamics (MD) and Crystal Plasticity (CP) are put together to solve it from atomic scale to mesoscopic scale. MD research indicates that the deformation of HX alloy occurs in two stages at temperature below 300 K: initially, as stacking fault deforms, stacking fault can transform into twinning with increasing strain. When the temperature exceeds 300 K, deformation primarily forms a stacking fault. The twinning deformation path transforms from intrinsic stacking fault to extrinsic stacking fault and then to twinning. A mesoscopic-scale CP model was developed using atomic-scale deformation mechanisms to bridge the gap between deformation mechanisms and experimental results. The CP results indicate a functional relationship between the strength of HX alloy and temperature. This relationship appears insensitive to crystal texture and grain shape. Incorporating grain morphology and texture into the model significantly impacts the strength response of calculating HX alloy. After the tensile deformation of HX alloy at 300 and 1173 K, the atomic scale deformation results characterized by transmission electron microscopy are aligned with the MD simulation results. The relationship between strength and temperature predicted by CP results has also been validated. A thorough investigation into the deformation behavior of HX alloys across different scales, employing MD and CP models, introduces a novel approach for predicting the mechanical properties of superalloys.

Effect of methyl methacrylate concentrations on surface and thermal analysis of composite polymer polymethylmethacrylates with mesogen reactive RM82

ABSTRACT This research report of the synthesis of composite polymers from liquid crystal mesogen reactive (RM82) monomers with Methyl methacrylate (MMA). The purpose of this research is analysis the effect concentration of MMA on the surface and thermal of the composite polymer PMMA-RM82. The result of the morphological analysis of composite surfaces performed by polarization optical microscopy (POM) technique showed liquid crystal textures affected composition from two monomers. SEM images show that the surface of the RM82 liquid crystal has a shape resembling fibrous and blade-like crystals with a length of up to 10 μm (micrometers). Analysis thermal showed the heat released by the PMMA-RM82 increased with the increase in MMA weight percent. This affects the rapid crystallization process of PMMA-RM82 which of concentration MMA 30%-RM82 the heat released is almost twice as much as the heat released by MMA 5%-RM82. The absence of PMMA and RM82 peaks both endothermic and exothermic in PMMA-RM82 samples indicates that polymerization has occurred and a new product has formed. Analysis structure molecule by FTIR found that the IR spectral form of each variation in the weight percent of MMA was almost the same, but there was a spectral shift that showed that polymerization had occurred in PMMA-RM82 which was characterized by a reaction to the free radical C=C bond released by the photoinitiator. XRD pattern of composite PMMA-RM82 showed the peaks formed are located at scattering angles similar to RM82 but there is a decrease in intensity as the percent weight of MMA increases.

Modular slot-die coater for in situ grazing-incidence x-ray scattering experiments on thin films.

Multimodal in situ experiments during slot-die coating of thin films pioneer the way to kinetic studies on thin-film formation. They establish a powerful tool to understand and optimize the formation and properties of thin-film devices, e.g., solar cells, sensors, or LED films. Thin-film research benefits from time-resolved grazing-incidence wide- and small-angle x-ray scattering (GIWAXS/GISAXS) with a sub-second resolution to reveal the evolution of crystal structure, texture, and morphology during the deposition process. Simultaneously investigating optical properties by in situ photoluminescence measurements complements in-depth kinetic studies focusing on a comprehensive understanding of the triangular interdependency of processing, structure, and function for a roll-to-roll compatible, scalable thin-film deposition process. Here, we introduce a modular slot-die coater specially designed for in situ GIWAXS/GISAXS measurements and applicable to various ink systems. With a design for quick assembly, the slot-die coater permits the reproducible and comparable fabrication of thin films in the lab and at the synchrotron using the very same hardware components, as demonstrated in this work by experiments performed at Deutsches Elektronen-Synchrotron (DESY). Simultaneous to GIWAXS/GISAXS, photoluminescence measurements probe optoelectronic properties in situ during thin-film formation. An environmental chamber allows to control the atmosphere inside the coater. Modular construction and lightweight design make the coater mobile, easy to transport, quickly extendable, and adaptable to new beamline environments.

Robustness of magnetocrystalline anisotropy and coercivity in Fe–Co–B

As a potential candidate for critical chemical element free permanent magnet, (Fe0.7Co0.3)2B, shows promising intrinsic magnetic properties, including large magnetization, high Curie temperature and moderate magnetocrystalline anisotropy (MCA). Still, the coercivity that has been achieved is relatively low. To understand and improve coercivity, we study the robustness of MCA related to the fluctuation of chemical composition and the structural distortion and its effect on coercivity in (Fe0.7Co0.3)2B from first principles DFT (density functional theory) calculation and micromagnetic simulation. A fluctuation of cobalt content of 10%, or 1% isotropic lattice strain, or 2% tetragonal distortion reduces MCA energy up to 30%. By considering randomly distributed local MCA energy reduction up to 30%, the calculated coercivity of anisotropic bulk magnets reduced from 3.6 kOe to 2.2 kOe. Rational microstructure design, such as grain size refinement and development of strong crystal texture of MCA easy-axis (i.e., degree of alignment for (Fe0.7Co0.3)2B grains), can enhance coercivity and mitigate the effect of local MCA reduction. In addition to acceptable intrinsic magnetic properties, the promising hard magnetic phase needs good MCA robustness to facilitate the development of practical magnets.

Stearate-Coated Biogenic Calcium Carbonate from Waste Seashells: A Sustainable Plastic Filler.

Waste seashells from aquaculture are a massive source of biogenic calcium carbonate (bCC) that can be a potential substitute for ground calcium carbonate and precipitated calcium carbonate. These last materials find several applications in industry after a surface coating with hydrophobic molecules, with stearate as the most used. Here, we investigate for the first time the capability of aqueous stearate dispersions to coat bCC powders from seashells of market-relevant mollusc aquaculture species, namely the oyster Crassostrea gigas, the scallop Pecten jacobaeus, and the clam Chamelea gallina. The chemical-physical features of bCC were extensively characterized by different analytical techniques. The results of stearate adsorption experiments showed that the oyster shell powder, which is the bCC with a higher content of the organic matrix, showed the highest adsorption capability (about 23 wt % compared to 10 wt % of geogenic calcite). These results agree with the mechanism proposed in the literature in which stearate adsorption mainly involves the formation of calcium stearate micelles in the dispersion before the physical adsorption. The coated bCC from oyster shells was also tested as fillers in an ethylene vinyl acetate compound used for the preparation of shoe soles. The obtained compound showed better mechanical performance than the one prepared using ground calcium. In conclusion, we can state that bCC can replace ground and precipitated calcium carbonate and has a higher stearate adsorbing capability. Moreover, they represent an environmentally friendly and sustainable source of calcium carbonate that organisms produce by high biological control over composition, polymorphism, and crystal texture. These features can be exploited for applications in fields where calcium carbonate with selected features is required.

Influence of film thickness on structural, optical, and electrical properties of sputtered nickel oxide thin films.

Utilizing radio frequency magnetron sputtering, we successfully fabricated nickel oxide thin films with different thickness (from 80 to 270 nm), and conducted an in-depth examination of their structural, morphological, optical, and electrical properties. The crystal structure and surface roughness were determined using x-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The XRD analyses showed that the films were composed of cubic nickel oxide, exhibiting a notable orientation along the (200) direction. This crystal texture partially increased when the film thickness reached 270 nm. In addition, a direct correlation between film thickness and crystallite size was observed, with the latter increasing as the former did. AFM analysis provided insights into the surface morphology, revealing metrics like the bearing area, 3D surfaces intersections, and statistical properties of surface height. These insights underscore the relationship between film thickness and surface properties, which in turn influence the overall electrical, and prominently, optical properties of the films. Employing transmittance UV-visible spectroscopy, we characterized the optical behavior of these films, noting a proportional increase in refractive index with film thickness. Additionally, resistivity was observed to increase concomitantly with film thickness. In conclusion, the deposition process's film thickness acts as a pivotal parameter for fine-tuning the structural, morphological, and optical properties of nickel oxide thin films. This knowledge paves the way for optimizing nickel oxide-based devices across various applications. RESEARCH HIGHLIGHTS: We synthesized and characterized of p-type semiconducting NiO thin films sputtered on substrates by using RF magnetron sputtering with different thickness. Advanced crystalline structures and fractal features extracted from XRD and AFM analysis. The 2D and 3Dsurface analysis of the samples indicates a complex structure with an imperfect self-similarity that suggests a multifractal structure. We represented graphically the relative representation of higher geometric objects in the AFM image. We attributed the optical and electrical properties of the samples to the crystallite size, and the concurrent reduction in oxygen vacancies and crystalline defects within the films.

Polyethylene glycol regulates the pitch and liquid crystal behavior of cellulose nanocrystal-based photonic crystals

Inspired by iridescent color in natural creations, cellulose nanocrystal (CNC) photonic crystals artificially created by nanotechnology have great application prospects due to their potential to control light propagation in the linear and nonlinear regimes. One of the most important development directions of photonic crystals is the diversification of colors, usually by adjusting the pitch. However, few researchers notice the effect of polymer molecular weight and content on pitch regulation and the interaction between polymer and CNC liquid crystals. Polyethylene glycol (PEG) were used as polymers to regulate the pitch of CNC photonic crystals and investigate the changes in microstructure, crystal structure, thermal properties, and liquid crystal texture of the composites by changing the PEG content and molecular weight. Different photonic crystal construction systems show that when the molecular weight of PEG is 0.4 k, it can be filled between CNCs to regulate the pitch of photonic crystals, while when the molecular weight of PEG is 20 k, it cannot always be filled between CNCs in evaporation-induced self-assembly (EISA) process due to the depletion interaction, which cannot effectively regulate the pitch. This study reveals the relationship between PEG and CNC liquid crystals, which supports the development of photonic crystals and the pitch regulation.

Unveiling the crystal and magnetic texture of iron oxide nanoflowers.

Iron oxide nanoflowers (IONF) are densely packed multi-core aggregates known for their high saturation magnetization and initial susceptibility, as well as low remanence and coercive field. This study reports on how the local magnetic texture originating at the crystalline correlations among the cores determines the special magnetic properties of individual IONF over a wide size range from 40 to 400 nm. Regardless of this significant size variation in the aggregates, all samples exhibit a consistent crystalline correlation that extends well beyond the IONF cores. Furthermore, a nearly zero remnant magnetization, together with the presence of a persistently blocked state, and almost temperature-independent field-cooled magnetization, support the existence of a 3D magnetic texture throughout the IONF. This is confirmed by magnetic transmission X-ray microscopy images of tens of individual IONF, showing, in all cases, a nearly demagnetized state caused by the vorticity of the magnetic texture. Micromagnetic simulations agree well with these experimental findings, showing that the interplay between the inter-core direct exchange coupling and the demagnetizing field is responsible for the highly vortex-like spin configuration that stabilizes at low magnetic fields and appears to have partial topological protection. Overall, this comprehensive study provides valuable insights into the impact of crystalline texture on the magnetic properties of IONF over a wide size range, offering a deeper understanding of their potential applications in fields such as biomedicine and water remediation.

Pulse-Electrodeposition and Growth Mechanism of Nanotwinned Copper Nanowires inside High Aspect-Ratio Anodic Aluminum Oxide

Nanotwinned copper (nt-Cu) has proven to possess many fascinating physical/chemical properties. However, it is still challenging to control the twin density and its orientation especially for high aspect-ratio Cu vias. Here, a matrix of nt-Cu nanowires (aspect ratio > 150) with dense coherent twin boundaries (CTBs) perpendicular to the growth direction were deposited in porous anodic aluminium oxide vias by pulse electrodeposition. We changed the pulse on/off duration to control the degree of (111) growth texture and twin density of the nt-Cu nanowires. A small anodic current in the pulse-off period enhanced (111) crystal texture and CTB formation during the bottom-up filling process. With the analysis of twin density, we proposed that the nanoscale twinning was activated by facet-dependent crystal growth and stress accumulation/relaxation behaviour during pulse electrodeposition. The interplay between on/off period and bias potential could modulate the twin density. Also, the sulfate adsorbates were proved to play an important role in the stress accumulation process. This study could be implemented in fabricating Cu interconnect in nanoelectronic devices and nanoelectromechanical systems. Figure 1

Machine learning studies for liquid crystal texture recognition

ABSTRACT Machine learning techniques such as local binary pattern algorithm and convolutional neural network were applied to study textures of liquid crystal compound (S)-4’-(1-methyloctyloxycarbonyl) biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]-benzoate (3F7HPhH7). This compound exhibits in its polymorphism several smectic phases (smectic A, ferroelectric smectic C and antiferroelectric smectic C) and two glass states of antiferroelectric smectic C phase, which textures are difficult to distinguish. Proof-of-concept evidence is provided, demonstrating the ability of machine learning algorithms to identify transition temperatures and the respective phases involved. The article describes the procedure for preparing a dataset of textures obtained from polarised microscopy for classification using convolutional neural networks, especially in cases where the image dataset is unbalanced. It utilises the feature of their self-similarity and image augmentation, particularly the cropping procedure. A Kolmogorov–Smirnov test was conducted to check if selected images do not carry the same information.

Coil Spring Failure Analysis Reviewed from Residual Stress, Crytal Orientation, and Texture

Crystal defects can be identified through the crystallographic characteristics of crystal orientation (lattice), microstrain, and texture. Identification of crystal defects on the atomic scale through crystallography is very important in analyzing the mechanism of material properties due to the influence of dislocations. The slip mechanism is analyzed to minimize coil spring failure. This study aims to analyze the causes of coil spring failure based on crystallography. XRD testing was carried out for analysis of residual stress, crystal orientation, and texture using MAUD 2.94 version software. Hardness testing was carried out on the surface of the coil spring with locations near and far from the fracture using micro Vickers. The macro fracture morphology was analyzed using a DSLR camera and the micro fracture morphology was analyzed using SEM. The XRD result shows that the coil spring material has a tensile residual stress value of "202.4 ± 15.9 MPa" with the resulting crystal orientation showing the hkl (100), (200), (211), (200) fields. The plane (200) has a texture characteristic that is oriented towards the Rolling direction along the spring axis. Texture oriented towards Rolling Direction can be shown with a maximum probability value of 1.191. A high probability will have an impact on the presence of material surface defects. Surface defects are indicated by the presence of pit corrosion on micro and macro fracture morphology observations. The pit corrosion defects that occur in the failed coil springs are the beginning of the formation of crack initiation and cause stress concentration. The stress concentration will increase with loading and cause crack propagation.

Low-cost BPO4 In Situ Synthetic Li3PO4 Coating and B/P-Doping to Boost 4.8V Cyclability for Sulfide-Based All-Solid-State Lithium Batteries.

Structural damage of Ni-rich layered oxide cathodes such as LiNi0.8Co0.1Mn0.1O2 (NCM811) and serious interfacial side reactions and physical contact failures with sulfide electrolytes (SEs) are the main obstacles restricting ≥4.6V high-voltage cyclability of all-solid-state lithium batteries (ASSLBs). To tackle this constraint, here, a modified NCM811 with Li3PO4 coating and B/P co-doping using inexpensive BPO4 as raw materials via the one-step in situ synthesis process is presented. Phosphates have good electrochemical stability and contain the same anion (O2-) and cation (P5+) as in cathode and SEs, respectively, thus Li3PO4 coating precludes interfacial anion exchange, lessening side reactivity. Based on the high bond energy of B─O and P─O, the lattice O and crystal texture of NCM811 can be stabilized by B3+/P5+ co-doping, thereby suppressing microcracks during high-voltage cycling. Therefore, when tested in combination with Li─In anode and Li6PS5Cl solid electrolytes (LPSCl), the modified NCM811 exhibits extraordinary performance, with 200.36 mAh g-1 initial discharge capacity (4.6V), cycling 2300 cycles with decay rate as low as 0.01% per cycle (1C), and 208.26mAhg-1 initial discharge capacity (4.8V), cycling 1986 cycles with 0.02% per cycle decay rate. Simultaneously, it also has remarkable electrochemical abilities at both -20 °C and 60 °C.

Liquid crystal textures, neural networks and art

ABSTRACT The ability to create art and advance science are distinguishing features of the human species. Currently, these fields are rarely interconnected. This publication presents liquid crystal textures in terms of their aesthetics. This manuscript covers issues from various fields of science and culture: physics, artificial intelligence, and art. The presented publications focuses on the textures of the following phases: nematic, smectic A, smectic B, smectic C, smectic B, smectic I, smectic F, smectic G, smectic H, ferroelectic smectic C and antiferroelectric smectic C. Images of these textures can serve as inspiration for creating new artwork using neural networks. Neural network algorithms like style transfer and DeepDream modified selected liquid crystal textures. The paper discusses the potential applications of the images obtained this way.

Investigation of microstructure and texture as related to primary recrystallization of grain-oriented silicon steel

Grain-oriented silicon steel requires a very strong Goss {110}<001> texture and as such a comprehensive control of thermo-mechanical processing parameters is required to achieve a strict control of texture. In particular the cold rolling and decarburization annealing process parameters have a determining effect on the grain size, the grain size distribution and the crystal texture distribution. In this study, the effect of cold rolling reduction on texture distribution in cold-rolled sheet has been analyzed. Secondary recrystallization of grain-oriented silicon steel is also highly dependent on the microstructure and texture after primary recrystallization. The influence of annealing temperature and carbides on the primary recrystallization process has also been investigated by measurements of grain growth and texture following primary recrystallization. By optimizing the microstructure and the texture of primary recrystallization of grain-oriented silicon steel, it is shown that a grain-oriented silicon steel exhibiting high magnetic induction low iron loss has been developed at Shougang Steel.

Highly Stable and Efficient Formamidinium-Based 2D Ruddlesden-Popper Perovskite Solar Cells via Lattice Manipulation.

Formamidinium (FA)-based 2D perovskites have emerged as highly promising candidates in solar cells. However, the insertion of 2D spacer cations into the perovskite lattice concomitantly introduces microstrain and unfavorable orientations that hinder efficiency and stability. In this study, by finely tuning the FA-based 2D perovskite lattice through spacer cation engineering, a stable lattice structure with balanced distortion, microstrain relaxation, and reduced carrier-lattice interactions is achieved. These advancements effectively stabilize the inherently soft lattice against light and thermal-aging stress. To reduce the photocurrent loss induced by undesired crystal texture, a polarity-matched molecular-type selenourea (SENA) additive is further employed to modulate the crystallization kinetics. The introduction of the SENA significantly inhibits the disordered crystallization induced by spacer cations and drives the templated growth of the quantum well structure with a vertical orientation. This controlled crystallization process effectively reduces crystal defects and enhances charge separation. Ultimately, the optimized FA-based perovskite photovoltaic devices achieve a remarkable power conversion efficiency (PCE) of 20.03% (certified steady-state efficiency of 19.30%), setting a new record for low-n 2D perovskite solar cells. Furthermore, the devices exhibit less than 1% efficiency degradation after operating at maximum power point for 1000 h and maintain excellent stability after thermal aging and cycles of cold-warm shock, respectively.

CO2 -Mediated Photocatalytic Chlorine Production Over Bismuth Oxychloride in Chloride Solution.

As one of the most commonly bulky chemicals, chlorine is conventionally manufactured by electrolysis of NaCl solution in the chlor-alkali process, which requires a huge supply of electrical energy. The photocatalytic route to produce chlorine by using solar energy and NaCl solution offers a promising strategy to reduce energy consumption and bring economic benefits. Herein, it was found that the introduction of CO2 would enhance the productivity of Cl2 from 8.24 μmol⋅h-1 to 39.6 μmol⋅h-1 in NaCl solution over BiOCl. Experimental studies reveal that the CO2 species (CO3 2- ) entered into the crystal texture of BiOCl and the interlayer space between [Bi2 O2 ]2+ slabs were increased and distorted, accelerating the cycle of Cl species. Besides, the cycle of carbonate species also existed and accelerated the reaction efficiency of Cl- oxidation to Cl2 . This work provides a new feasible method of using abundant CO2 resources to accelerate the process of chlorine production via photocatalysis.

Micromagnetic simulation of electrochemically deposited Co nanowire arrays for wideband microwave applications

We study the magnetic properties of arrays of Co nanowires which exhibit zero bias-field ferromagnetic resonance absorptions in a 0–30 GHz range. Columnar arrays of Co nanowires with lengths of 8–15 µm were electrochemically grown using ∼20 µm thick anodic alumina membranes with 50 nm pore diameters. Microstructural, static magnetic, and microwave properties of five different nanowire arrays were characterized. The studied Co nanowires present different crystal structure textures and magnetic properties. The static magnetic loop shapes and the ferromagnetic resonance frequencies of the nanowire arrays were correctly reproduced using the Mumax3 micromagnetic software. For each sample input parameters dependent on the x-ray diffraction and microstructural data, were fine-tuned to allow the best fit of the experimental hysteresis loops and the related microwave spectra. Using this method, it was possible to analyze the rather complex interplay between geometry and magneto-structural features of the different arrays, defining which parameters play a key role in the development of nano-systems with specific microwave properties.