Annealing Conditions Research Articles

Effects of Bath Composition, Current Density and Annealing Conditions on the Properties of the Electrodeposited Ni Seed Layer for Cu Contacts in Si Solar Cells

Effects of Bath Composition, Current Density and Annealing Conditions on the Properties of the Electrodeposited Ni Seed Layer for Cu Contacts in Si Solar Cells

A large-scale transcontinental river system crossed West Antarctica during the Eocene.

Extensive ice coverage largely prevents investigations of Antarctica's unglaciated past. Knowledge about environmental and tectonic development before large-scale glaciation, however, is important for understanding the transition into the modern icehouse world. We report geochronological and sedimentological data from a drill core from the Amundsen Sea shelf, providing insights into tectonic and topographic conditions during the Eocene (~44 to 34 million years ago), shortly before major ice sheet buildup. Our findings reveal the Eocene as a transition period from >40 million years of relative tectonic quiescence toward reactivation of the West Antarctic Rift System, coinciding with incipient volcanism, rise of the Transantarctic Mountains, and renewed sedimentation under temperate climate conditions. The recovered sediments were deposited in a coastal-estuarine swamp environment at the outlet of a >1500-km-long transcontinental river system, draining from the rising Transantarctic Mountains into the Amundsen Sea. Much of West Antarctica hence lied above sea level, but low topographic relief combined with low elevation inhibited widespread ice sheet formation.

Cu2O/CuO composite for efficient performance in photoelectrochemical and optoelectronics applications

This study introduces a highly active photoelectrode, comprising a Cu2O/CuO composite, synthesized through annealing Cu2O thin film under controlled conditions to induce partial oxidation. Through systematic investigation of annealing conditions, including temperature and duration, an optimal synthesis condition of 400 °C for 1 h was identified, resulting in superior photoelectrochemical and optoelectronic properties. It yielded the most favorable outcomes, exhibiting the largest charge carrier density of 1.09 × 1021 cm−3, lowest charge transfer resistance of 18.8 Ω, and highest photocurrent density of −2.97 mA cm−2 with stability of 81%. This performance enhancement, which surpassed the initial photocurrent by 7 times under AM 1.5 simulated sunlight illumination at 0 V versus the reversible hydrogen electrode (RHE), is attributed to the formation of the Cu2O/CuO composite. This composite facilitates improved electron-hole pair separation efficiency, while the narrow bandgap of CuO enables enhanced light absorption. Additionally, the stability of the photocurrent is significantly improved by 2.3 times, attributed to the protective function of the CuO layer on Cu2O. Thus, the Cu2O/CuO composite emerges as a highly efficient and promising photocathode, offering a facile and cost-effective route for photoelectrochemical and optoelectronics applications.

High χ P2PFBEMA-b-P2VP Block Copolymers Forming 6-8 nm Domains for Semiconductor Lithography.

We leveraged the potential of high χ-low N block copolymer (BCP), namely, poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (P2PFBEMA-b-P2VP), and demonstrated its utility in next-generation nanomanufacturing. By combining molecular dynamics simulations with experiments, the χ value was calculated to be as high as 0.4 (at 150 °C), surpassing similar structures. Highly ordered features suitable for application were observed, ranging in periods from 19.0 nm down to 12.1 nm, with feature sizes as small as 6 nm. Transmission electron microscopy images of the BCP solutions indicated that preformed micelles in the solution facilitated the self-assembly process of the thin film. In addition, the vertical or parallel orientation of the cylindrical structure was determined by manipulating the solvent, substrate, and annealing conditions. Finally, guided by a wide topographical template, nearly defect-free directed self-assembly (DSA) lines with a resolution of 8 nm were achieved, highlighting its potential practical application in DSA lithography technology.

Temperate Versus Arctic: Unraveling the Effects of Temperature on Oil Toxicity in Gammarids.

Shipping activities are increasing with sea ice receding in the Arctic, leading to higher risks of accidents and oil spills. Because Arctic toxicity data are limited, oil spill risk assessments for the Arctic are challenging to conduct. In the present study, we tested if acute oil toxicity metrics obtained at temperate conditions reflect those at Arctic conditions. The effects of temperature (4 °C, 12 °C, and 20 °C) on the median lethal concentration (LC50) and the critical body residue (CBR) of the temperate invertebrate Gammarus locusta exposed to water accommodated fractions of a fuel oil were determined. Both toxicity metrics decreased with increasing temperature. In addition, data for the temperate G. locusta were compared to data obtained for Arctic Gammarus species at 4 °C. The LC50 for the Arctic Gammarus sp. was a factor of 3 higher than that for the temperate G. locusta at 4 °C, but its CBR was similar, although both the exposure time and concentration were extended to reach lethality. Probably, this was a result of the larger size and higher weight and total lipid content of Arctic gammarids compared to the temperate gammarids. Taken together, the present data support the use of temperate acute oil toxicity data as a basis for assessing risks in the Arctic region, provided that the effects of temperature on oil fate and functional traits (e.g., body size and lipid content) of test species are considered. As such, using the CBR as a toxicity metric is beneficial because it is independent of functional traits, despite its temperature dependency. To the best of our knowledge, the present study is the first to report CBRs for oil. Environ Toxicol Chem 2024;43:1627-1637. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Thermal imaging can reveal variation in stay-green functionality of wheat canopies under temperate conditions.

Canopy temperature (CT) is often interpreted as representing leaf activity traits such as photosynthetic rates, gas exchange rates, or stomatal conductance. This interpretation is based on the observation that leaf activity traits correlate with transpiration which affects leaf temperature. Accordingly, CT measurements may provide a basis for high throughput assessments of the productivity of wheat canopies during early grain filling, which would allow distinguishing functional from dysfunctional stay-green. However, whereas the usefulness of CT as a fast surrogate measure of sustained vigor under soil drying is well established, its potential to quantify leaf activity traits under high-yielding conditions is less clear. To better understand sensitivity limits of CT measurements under high yielding conditions, we generated within-genotype variability in stay-green functionality by means of differential short-term pre-anthesis canopy shading that modified the sink:source balance. We quantified the effects of these modifications on stay-green properties through a combination of gold standard physiological measurements of leaf activity and newly developed methods for organ-level senescence monitoring based on timeseries of high-resolution imagery and deep-learning-based semantic image segmentation. In parallel, we monitored CT by means of a pole-mounted thermal camera that delivered continuous, ultra-high temporal resolution CT data. Our results show that differences in stay-green functionality translate into measurable differences in CT in the absence of major confounding factors. Differences amounted to approximately 0.8°C and 1.5°C for a very high-yielding source-limited genotype, and a medium-yielding sink-limited genotype, respectively. The gradual nature of the effects of shading on CT during the stay-green phase underscore the importance of a high measurement frequency and a time-integrated analysis of CT, whilst modest effect sizes confirm the importance of restricting screenings to a limited range of morphological and phenological diversity.

Bi-environmental evaluation of oat (Avena sativa L.) genotypes for yield and nutritional traits under cold stress conditions using multivariate analysis

AbstractOat being a rabi/winter crop in Kashmir, experiences extremely low temperatures which has detrimental effects on its growth and development. Therefore, this study was designed to evaluate a set of 130 oat genotypes in multi-location trials across temperate conditions of Kashmir valley from 2018 to 2022. From the preliminary data of 56 genotypes, including five checks, were selected and evaluated for nutritional and yield attributing traits under cold stress conditions at two locations. The results demonstrated significant genetic variation and high heritability for majority of traits, except for days to 50% flowering, days to maturity and dry fodder. Positive correlations were observed between green fodder yield and other traits, indicating their potential for enhancing yield. Principal component analysis identified four principal components that accounted for 69.87% of the total variation. Cluster analysis categorized the genotypes into two main clusters and six sub-clusters. Frost damage assessment was conducted at tillering stage after the snow melted in late January 2021 and 2022 using cold tolerance rating scale and subsequently tested for chilling injury through an electrolyte leakage test. From field and lab data analysis, five most promising cold tolerant, nutritious and high-yielding genotypes were identified. These genotypes have significant potential for utilization in future breeding programmes to improve cold tolerance in cultivated oats within the Kashmir valley thus promoting agricultural productivity and sustainability. The outcomes also provide valuable insights into the genetic variation, heritability, genotype-by-environment interactions, correlations and cold tolerance of oat genotypes in Kashmir.

Characterizing of a unique Al/Cu FGMMC fabricated via the ARB-CRB process followed by annealing

This study investigates the influence of different annealing temperatures on the microstructure and growth of the intermetallic phase in an Al/Cu functionally graded metal matrix composite (FGMMC ( produced by the accumulative roll bonding (ARB)-cold roll bonding (CRB) process. SEM images show the evolving distribution of Cu content in the composite, with the finest and thinnest Cu layer observed in the Al/20Cu region. The annealing at 400°C and 450°C for 2, 4, and 6 hours results in the formation of intermetallic layers (Al2Cu, Al4Cu9, and AlCu) with a clear progression from the Al side to the Cu side, as confirmed by SEM-EDS and TEM analysis. Increasing the annealing conditions increases the thickness of the intermetallic layers. In addition, the intermetallic layers are thicker in the FGMMC sample than in the ARB sample under the same conditions due to the additional strain during the process. The findings demonstrate that a diffusion-controlled mechanism governs the growth of the Al2Cu, Al4Cu9, and AlCu layers. The tensile test results indicate that as the Cu content increases from 20 wt% to 80 wt%, the ultimate tensile strength of the layers increases from 288.24 MPa to 373.66 MPa, while the elongation decreases from 8.2 % to 5.3 %. After annealing, however, these values decreased due to the restoration phenomenon and intermetallic formation. The fracture surface predominantly exhibits a brittle mode, especially with increasing Cu content and annealing conditions.

Myiasis in a Backyard Pig: A Case Report

Background: Myiasis is a parasitic infestation of livestock animals caused by dipteran larvae. The presence of wounds, lack of hygiene on the farm, and temperate climatic conditions contribute to myiasis. Swine can be infested by myiasis if injured pigs are not treated properly and failure to treat myiasis in time may cause the culling or death of the pigs, resulting in huge economic loss to the farmers. But like humans and other farm animals, pigs also deserve to be treated and cured of any suffering or disease. Therefore, this study is documented on pig myiasis and its management because to date a few cases have been reported on it. Case presentation: This case report documented the successful management of neck myiasis in a male, 9-month-old, 12-kg-weighing backyard pig. The wound site was cleaned using antiseptics and maggots were removed. The site was treated with turpentine oil, and ivermectin at 0.2 mg/kg B.W. and S/C. A combination of streptomycin (12.5 mg/kg B.W.) and penicillin (20000 IU/kg B.W.) was used IM daily for 5 days to prevent secondary bacterial infection. The wound was dressed regularly on every alternate day until the complete removal of maggots and the formation of granulation tissue. Conclusion: Through proper therapeutic management, the backyard pig’s neck myiasis wound was successfully healed in 10 days without any complications.

Enhanced contact performance of high-brightness micro-LEDs via ITO/Al anode stack and annealing process

Micro-light-emitting diodes (Micro-LEDs) are a new type of display device based on the third-generation semiconductor gallium nitride (GaN) material which stands out for its high luminous efficiency, elevated brightness, short response times, and high reliability. The contact between anode layers and P-GaN is one of the keys to improving the performance of the devices. This study investigates the impact of electrode structure design and optimized annealing conditions on the anode contact performance of devices. The Micro-LED device with the size of 9.1 μm whose electrode structure is ITO/Ti/Al/Ni/Cr/Pt/Au (100/50/350/100/500/500/5000 Å) exhibits a significant improvement in contact performance after annealing under the Ar gas atmosphere at 500 °C for 5 min. The optimized device exhibited a current of 10.9 mA and a brightness of 298,628 cd/m2 under 5 V. The EQE peak value of Device A is 10.06% at 400 mA.

Etiology, management, and host response of cold-tolerant maize germplasm for common rust disease of maize under temperate conditions

Etiology, management, and host response of cold-tolerant maize germplasm for common rust disease of maize under temperate conditions

Formation of an extended defect cluster in cuprous oxide

Intrinsic defects and defect clusters play an important role in the room-temperature transport of cuprous oxide. Neutralization of these defects by doping and/or modifying the synthesis process is essential to improve the room-temperature hole mobility in cuprous oxide. Toward this end, we annealed polycrystalline cuprous oxide under Cu-rich conditions, which led to the neutralization of the intrinsic acceptor defect. The concentration of both the acceptor defects ( VCu and VCusplit ) that are already present, reduces by four to five orders of magnitude. This is in accordance with the amount of possible Cu incorporation under different annealing conditions, indicating the backfilling of a large fraction of the Cu vacancies. Unforeseeably, the experimental conditions lead to the creation of yet another higher-order extended defect (3 VCu + 2Cu i ) with a defect level at ≈0.5 eV above the valence band. The formation of such a defect is also indirectly suggested by the analysis of carrier concentration vs. temperature data and first-principles calculations. Such singly ionized higher-order defects with a possibly higher capture cross-section act as more effective traps resulting in reduced hole mobility.

Viability of an Open-Loop Heat Pump Drying System in South African Climatic Conditions

Drying agricultural produce consumes a considerable amount of energy. As an energy-efficient system, a heat pump can improve the energy efficiency of the drying process and hence reduce the energy consumption, especially in South Africa, where both sub-tropical and temperate weather conditions dominate. The objective of this research is to experimentally investigate the impacts of weather conditions on the operational conditions and thermal performance of an open-loop air-source heat pump drying system. The experimental investigation was conducted in a climate chamber where the climate conditions were simulated from −10 °C to 20 °C with an interval of 10 °C for the typical temperature range of the harvesting season in South Africa. The findings indicate that ambient temperatures have a significant impact on both the operating conditions and thermal performance of an open-loop heat pump system; the change in ambient temperatures from −10 °C to 20 °C leads to a 141.6% improvement in the suction pressure, a 214.2% increase in the discharge pressure, and 30.1% increase in the compression ratio, as well as a consequent increase of 130.6% in the refrigerant mass flow rate (from 0.0067 to 0.0155 kg/s), resulting in a corresponding increase in the coefficient of performance (COP) of the heat pump drying system by about 42.1%. Therefore, this study suggests that, while using an open-loop air-source heat pump drying system utilising R134a refrigerant is feasible in South Africa, it may be practically limited to regions with warm climates or during warmer seasons.

Highly Sensitive Diethylamine Detection at Room Temperature Using g-C3N4 Nanosheets Decorated with CuO Hollow Polyhedral Structures.

Chemiresistive-based metal oxide semiconductor (MOS) gas sensors are widely used in gas sensing due to their advantageous properties. Graphitic carbon nitride (g-C3N4) and metal oxide heterostructure materials can improve charge transport properties, selectivity, and sensitivity in MOS gas sensor materials. Herein, for the first time, CuO hollow polyhedral structures (HPSs) were synthesized via a hydrothermal technique and annealed at different temperatures, with the 400 °C annealed (CuO-400 HPSs) demonstrating remarkable sensing capabilities for diethylamine (DEA) gas at room temperature (RT). The x-g-C3N4 nanosheets were decorated with CuO HPSs in varying amounts (x = 0.8, 1.8, 2.1, and 3.1 wt %) and then annealed at 400 °C for x-g-C3N4-CuO-400 hollow polyhedral heterostructures (HPHSs). Indeed, among the synthesized samples, the 1.8%-g-C3N4-CuO-400 HPHSs have a higher sensitivity to DEA (resistance change in gas (Rg) and air (Ra); Rg/Ra= 65 @ 20 ppm), a low detection limit (Rg/Ra= 6 @ 500 ppb), wide dynamic response (Rg/Ra= 190 @ 80 ppm), strong stability (30 days), and 21.6 times higher sensitivity than pure CuO at RT toward 20 ppm of DEA. The exceptional gas-sensing behavior can be attributed to various factors, including controlled annealing conditions that result in the formation of well-defined structures and greater porosity, efficient charge transfer properties resulting from an optimized ratio of g-C3N4 to CuO in HPHSs, an abundance of defects, unsaturated Cu sites, and synergistic effects. The study presents a universal strategy for generating sensitive and selective g-C3N4-based composite materials for low-temperature gas sensors.

Annealing response and yielding behavior of cold rolled advanced HSLA steels

High-strength low-alloy (HSLA) steel is well established in car body manufacturing. They comprise a lean low-carbon alloy concept and can be produced by a wide variety of processing routes. However, cold-rolled HSLA steels are typically limited to a yield strength of 460 MPa by current standards. This research work will present a concept of extending the yield strength range of cold-rolled HSLA steels to above 500 MPa. A key aspect is to find the right balance between recovery and recrystallization of the cold rolled matrix during the annealing stage thereby mitigating the influence of solute and precipitated niobium. Additional solute draging power was introduced by alloying molybdenum to one of the investigated steels. A detailed microstructural analysis using transmission electron microscopy revealed that under recovery annealing conditions an ultrafine-grained microstructure with ferrite grain sizes between 0.5 and 1 μm can be established leading to large strength contribution via the Hall-Petch relationship. Strength losses related to partial recrystallization can be recovered to an extent of around 200 MPa by the precipitation of nano-sized niobium carbide particles. It is demonstrated that the presence of niobium and molybdenum in solute condition have the most prominent influence on obstructing recrystallization via solute drag. It is furthermore shown that the magnitude of precipitation strengthening correlates with the Lüders strain. The analysis of the work hardening behavior indicated that the n-value in ultrafine-grained condition approaches a lower limit value of 0.03 and raises to above 0.2 with progressing recrystallization as well as precipitation strengthening. The detailed evaluation of the tensile characteristics indicates that the strength limit for these HSLA steels ranging between 830 and 880 MPa is reached when the average grain size is reduced to 0.46 μm. The results of this study used to define robust processing conditions to securely produce steel grades in the 600–800 MPa yield strength range.

Novel Hybrid Ferromagnetic Fe–Co/Nanodiamond Nanostructures: Influence of Carbon on Their Structural and Magnetic Properties

This study introduces a novel magnetic nanohybrid material consisting of ferromagnetic (FM) bcc Fe–Co nanoparticles (NPs) grown on nanodiamond (ND) nanotemplates. A combination of wet chemistry, which produces chemical precursors and their subsequent thermal treatment under vacuum, was utilized for its development. The characterization and study of the prepared samples performed with a range of specialized experimental techniques reveal that thermal treatment of the as-prepared hybrid precursors under a range of annealing conditions leads to the development of Co-rich Fe–Co alloy NPs, with average sizes in the range of 6–10 nm, that exhibit uniform distribution on the surfaces of the ND nanotemplates and demonstrate FM behavior throughout a temperature range from 2 K to 400 K, with maximum magnetization values ranging between 18.9 and 21.1 emu/g and coercivities ranging between 112 and 881 Oe. Moreover, 57Fe Mössbauer spectroscopy reveals that apart from the predominant bcc FM Fe–Co phase, iron atoms also participate in the formation of a secondary martensitic-type Fe–Co phase. The emergence of this distinctive phase is attributed to the diffusion of carbon atoms within the Fe–Co lattices during their formation at elevated temperatures. The source of these carbon atoms is related to the unique morphological properties of the ND growth matrices, which facilitate surface sp2 formations. Apart from their diffusion within the Fe–Co NP lattice, the carbon atoms also reconstruct layered graphitic-type nanostructures enveloping the metallic alloy NPs. These non-typical nanohybrid materials, reported here for the first time in the literature, hold significant potential for use in applications related, but not limited to, biomedicine, biopharmaceutics, catalysis, and other various contemporary technological fields.

Reversible Polarity Control in 2D MoTe2 Field‐Effect Transistors for Complementary Logic Gate Applications

AbstractPrecise control over polarity in field‐effect transistors (FETs) plays a pivotal role in the design and construction of complementary metal–oxide–semiconductor (CMOS) logic circuits. In particular, achieving such precise polarity control in 2D semiconductors is crucial for the further development of advanced electronic applications beyond unit devices. This paper presents a systematic investigation on the reversible transition of carrier types in a 2D MoTe2 semiconductor under different annealing atmospheres. Photoemission spectroscopy and density functional theory (DFT) calculations demonstrate that annealing processes in vacuum and in ambient air induce a modification in the density of states, resulting in alterations in p‐type or n‐type characteristics. These reversible changes are attributed to the physisorption and elimination of oxygen on the surface of MoTe2. Furthermore, it is found that the device geometry affects the polarity of the transistor. By strategically manipulating both the annealing conditions and the geometric configuration, the n‐ and p‐type unipolar characteristics of MoTe2 FETs are successfully modulated and ultimately demonstrating that the functionality of not only a complementary inverter with a high voltage gain of ≈20, but also more complex logic circuits of NAND and NOR gates.

Enabling high capacity and reversible Li storage in indium(III) oxide anode surrounded by carbon nanotube matrix

In2O3 is one of the post-transition metal oxides that can be a potential anode material for the Li-ion batteries (LIBs) because of its high theoretical capacity (869 mAh g−1) and low operating voltage (0.8 V vs Li/Li+) compared to other metal oxides. However, they have rarely been used in practical applications because of typical challenges such as irreversible capacity, unstable cycling stability, and poor coulombic efficiency. In this study, carbon nanotubes (CNTs) were successfully combined with In2O3 nanoparticles (NPs) via a solvothermal process. The In2O3 NPs and CNTs were homogeneously mixed by controlling the CNT dispersion (functionalization and appropriate solvent) and mixing sequence (dissolving the In2O3 precursor in the CNT-dispersed solution followed by thermal annealing). In addition, an increase in the oxygen vacancies in the In2O3 NPs by controlling the thermal annealing conditions (In2O3/CNT_Ar) could enhance robust binding with CNTs, increase the number of Li-ion binding sites, and improve the electrical conductivity. Therefore, at an appropriate ratio of In2O3 and CNT (92:8, w/w), the In2O3/CNT_Ar demonstrated remarkable cycling performance (830 mAh g−1 at a current density of 200 mA g−1 after 100 cycles) and rate capability (65% retention at 5 A g−1 relative to 100 mA g−1), which outperformed most In2O3-based anodes previously studied. Therefore, In2O3/CNT_Ar is a promising anode material for use in next-generation LIBs.

Amorphous ribbons for GMI detection of stray fields FeOx magnetic filler of epoxicomposites

Magnetoimpedance (MI) effect in stress-annealed Co-based amorphous ribbon was studied in the states without and in presence of the magnetic epoxy composite of cylindrical shape. Iron oxide FeOx magnetic microparticles of different concentrations (0–70 wt.%) were used as a magnetic filler. The condition of stress annealing (350 °C, 1 h and 250 MPa specific load) were selected in order to insure the high MI sensitivity with respect to external magnetic field in the field of a few Oersted. The MI responses were modified in the presence of the magnetic epoxy composites due to the contribution of the stray fields of embedded microparticles. It was experimentally found that degree of the MI curves modification depended on the microparticles concentration. The MI characteristics were also dependent on the length-to-width ratio of the MI element. The most sensitive MI element under study showed a linear dependence with a 1 %/weightpercent microparticle concentration slope. Mathematical modeling using finite elements (FEM) protocol for the properties of short MI elements confirmed the results and highlighted the non-monotonic contribution of high-concentration composites to the MI responses.

Increasing the capacity of pseudocapacitive WO3 auxiliary electrode for enhanced two-step decoupled acid water electrolysis

Decoupled water electrolysis has all the necessary properties to become an effective hydrogen production tool. Hydrogen evolution is decoupled from oxygen evolution using red-ox mediator electrodes in decoupled electrolysis. Therefore, oxygen and hydrogen are not produced simultaneously or in the same space. This simplifies the design of electrolysers and opens up the possibility of not using membranes and diaphragms for gas separation as conventional electrolysers do. Also, membrane-free technology improves the durability and efficiency of electrolysers. The reduction and oxidation of the red-ox mediator electrode must be reversible. Also, the electrode material should have a high charge capacity and be durable. In this work, we demonstrate WO3 as a red-ox mediator electrode in decoupled water electrolysis with acid electrolyte and investigate the effect of lyophilisation and annealing conditions on WO3 capacity. Indeed, the WO3 electrode can successfully act as a red-ox mediator through intercalation and deintercalation of H+ ions. Lyophilisation increases capacity more than two times than the air-dried sample, 495.55 and 201.41 F/g, respectively. Such high capacities as 837.43 F/g were reached when an inert annealing atmosphere was used. The electrolysis faradaic efficiency of 98–99 % was achieved in all prepared samples, with an energetical efficiency of 34–58 %.