Cerium substituted yttrium iron garnet films with a chemical formula Y3−xCexFe5O12 (x=0.0–0.3) have been successfully prepared by a sol–gel method. The microstructure analysis showed that all films ...exist in the cubic garnet structure. The lattice parameter and grain size increased with the increment of Ce concentrations up to 0.25, indicating the complete Ce substitution in yttrium site. For a film with x=0.3, the lattice parameter remained unchanged and grain size decreased. The film thickness increased and surface roughness varied with the increment of Ce content. All of the films have high optical transparency (above 80%). The Ce content reduced the saturation magnetization of the film up to a certain limit where above this limit the value increased. Overall, the findings showed that the films with x≤0.25 exhibited very excellent properties, hence they are promising materials for magneto-optical devices.
•The maximum substitution of Ce3+ ions in the CexY3−xFe5O12 sol-gel film was x = 0.25.•The Ce content reduced the saturation magnetization (Ms) of the film at a certain x value then the Ms increased.•The coercivity values of films indicate there are multi domain and single domain film.•The films with x≤0.25 are suitable to be applied in magneto-optical devices.
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•YIG films with grain size <12 nm were prepared by a sol-gel method.•The saturation magnetization decreases with increasing temperature from 10 to 300 K.•The coercivity decreases with increasing ...temperatures from 10 to 300 K.•The Curie temperature is in the range of 554 to 601 K.
We report on YIG film with small grain size (<12 nm) that has the potential to be used in microwave device application. The nanostructured film has been deposited on quartz substrate by a sol-gel spin coating technique, followed by annealing at temperatures in the range between 700 and 900 °C. The structural and magnetic properties of the film in the range 10–610 K were investigated. The X-ray diffraction results demonstrate that the films formed in a polycrystalline structure with lattice parameter in the range of 12.249–12.359 Å, lower than that of bulk materials. The saturation magnetization decreased not linearly with increasing the temperature from 10 to 300 K, differently from that reported for the bulk YIG. The coercivity value decreased with increasing temperatures (10–300 K), except for the film annealed at 800 °C. The Curie temperature of the film annealed at 700 °C was 554 K, however, other films showed higher Curie temperature values than that reported for bulk YIG. These properties are strongly influenced by the stress in the film’s structure due to the different thermal expansion coefficient of the YIG and the quartz substrate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Cerium substitute Y2.8−xDy0.2CexFe5O12 (x=0, 0.2, 0.25, 0.3, 0.35) films have been prepared on quartz substrates by a simple sol–gel method and followed by a spin-coating technique. The crystalline ...structures, surface and magnetic properties of the films has been investigated by an X-ray diffractometer (XRD), a field emission scanning electron microscope (FESEM), an atomic force microscope (AFM) and a vibrating sample magnetometer (VSM). The XRD analysis revealed that the films have garnet structure. The lattice parameter increased as Ce content was increased up to 0.25 due to the Ce3+ ions completely substituted for Y3+ ions. For films x≥0.3, the lattice parameter decreased. The FESEM results showed that the average grains were small, ranging from 11 to 14nm and the thickness of films increased with the increment of Ce contents. VSM results for both in and out-plane magnetic measurement showed the film with x=0 has the highest saturation magnetization (Ms) values. With the increment of Ce contents, the Ms of films decreased due to the substitution of Ce3+, Dy3+ ions in the c-site. For films x≥0.3 the reduction of Ms values was due to the presence of CeO2 in the film. The films with x=0–0.25 exhibited increases in Hc values. The improvement of coercivity value, small grain size and high crystalline structure of film with x=0.25 has a potential to be used in magneto optical (MO) memory storage applications.
•Ce-doped Y2.8−xDy0.2CexFe5O12 films were prepared by the sol–gel method.•The solubility limit of Ce3+ ions in the film was x=0.25.•The average grain size ranging from 11 to 14nm with the increment of Ce doping.•Increasing Ce contents degrades the saturation of magnetization of films.•Increasing Ce contents improve the coercivity of films.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Hydrogen energy storage systems (HydESS) and their integration with renewable energy sources into the grid have the greatest potential for energy production and storage while controlling grid demand ...to enhance energy sustainability. This paper presents a bibliometric analysis based on a comprehensive review of the highly cited articles on HydESS to provide a detailed insight into future directions and applications. The study was carried out by using the Scopus database search engine to look for filtered keywords in the HydESS and related research. It can be demonstrated that the HydESS literature expanded rapidly from 2016 to 2021 compared to 2011 to 2015. It is found that 89.17% of published articles explained control and test systems-based methods, whereas 10.83% of publications discuss review assessments. Our analysis of highly cited articles on HydESS highlights several aspects, such as methods and systems, issues, difficulties, and challenges to establishing current constraints and research gaps. This evaluation can enhance operational performance, environmental friendliness, energy savings, uninterrupted power supply service, cost benefits, on-site generation, and adaptability. It would be beneficial for technology development and the growth of the hydESS industry. This study may act as a guideline not only for academics in determining the line of research and generating additional discoveries, but also for the government in formulating financial strategies.
•Top-cited hydrogen energy storage system articles are reviewed under specific conditions.•Hydrogen storage integrated grids have the potential for energy sustainability.•A historical overview of hydrogen storage was analyzed using the Scopus database.•This survey has exhibited a developing hydrogen storage and renewable energy fields of research.•Bibliometric analysis was used to identify potential future research directions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study presents a bibliometric review focusing on the utilization of water electrolysis as a means of generating hydrogen as an energy carrier. The analysis includes research conducted over the ...past decade, covering from 2014 to 2023 (till August). Several key aspects are highlighted, including publication trends, the leading country in research output, journal rankings, and a citation analysis of papers related to water electrolysis. The findings reveal a notable increase in publication trends, with China emerging as the leading contributor in this research area. Furthermore, the International Journal of Hydrogen Energy is identified as the highest-ranked journal in terms of both publication number and citation impact. Additionally, the top ten most cited research articles and review papers are investigated to determine their influence within the field. To gain a deeper understanding of water electrolysis methods, the three primary approaches: alkaline water electrolysis (AWE), proton exchange membrane (PEM) electrolysis, and solid oxide electrolysis (SOE) is examined. The analysis emphasizes that PEM electrolysis is the most prevalent method for hydrogen generation, particularly when integrated with renewable energy sources such as solar and wind power due to its rapid response to electrical input fluctuation. Finally, the challenges and future directions of water electrolysis in hydrogen production are highlighted, including an exploration of economic and environmental considerations at large scale, offering insights into the path forward for advancing this technology sustainably.
•A comprehensive bibliometric analysis of water electrolysis for hydrogen production.•Publication trends, journal rankings, and citation analysis are highlighted.•China is identified as the leading contributor in water electrolysis publications.•International Journal of Hydrogen Energy: the highest-ranked journal in this field.•Specific electrolysis methods, including AWE, PEM, and SOE are examined.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This article deals with the development of an intelligent fuzzy logic controller for solid-state transfer switch toward fast fault detection and power transfer to the alternative feeder. A set of ...fuzzy rules are developed for the controller which in turn shift the loads from the preferred feeder to the alternate feeder with quality power resolving fault interruption or voltage sags. The voltage and the current control loop generate a signal to the fuzzy control block to provide an on or off pulse for the switches upon activate fuzzy rules in the interference engine. In this article, a compilation of 35%, 50%, 70%, and 100% faults are created to demonstrate the effectiveness of the proposed fuzzy controller toward detecting fault levels and transferring power to the desired feeder. It was discovered that the proposed fuzzy logic controller detects faults in the range of 0.054 to 0.061 milliseconds and transfers power in the range of 1.742 to 3.107 ms, which is significantly faster and more reliable than the existing literature.
Sustainable energy demand drives innovation in energy production. Electrolysis of water can produce carbon-free hydrogen from renewable sources. This paper presents a bibliometric analysis of recent ...and highly referenced research on hydrogen electrolysers utilising the Scopus database to shed insight into future trends and applications. It has been discovered that the most frequently published type of study for top-ranked papers is the formulation of problems and simulations (38.3%), followed by a study of the state-of-the-art technology assessment (32.5%), laboratory research, design, and performance evaluation (24.2%), and reviews (5%). In general, 33.33% of articles focused on controlling hydrogen electrolyser efficiency. This study used different case studies from the global literature to conduct a complete evaluation of the electrolyser statistical analysis of the present state of the art, models or modes of operation, key challenges, outstanding issues, and future research. This evaluation will aid researchers in building a commercially successful hydrogen electrolyser.
•A comprehensive review on hydrogen electrolyser is analysed for future research directions.•The problems, state-of-the-art technology, design, and performance evaluation is reviewed.•The control strategies are significantly boost the efficiency of hydrogen electrolysers.•A statistical analysis on electrolyser models, open issues, and future research trend is investigated.•This review will contribute to improve the efficiency and sustainability of electrolyser technology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The advancement of hydrogen technology is driven by factors such as climate change, population growth, and the depletion of fossil fuels. Rather than focusing on the controversy surrounding the ...environmental friendliness of hydrogen production, the primary goal of the hydrogen economy is to introduce hydrogen as an energy carrier alongside electricity. Water electrolysis is currently gaining popularity because of the rising demand for environmentally friendly hydrogen production. Water electrolysis provides a sustainable, eco-friendly, and high-purity technique to produce hydrogen. Hydrogen and oxygen produced by water electrolysis can be used directly for fuel cells and industrial purposes. The review is urgently needed to provide a comprehensive analysis of the current state of water electrolysis technology and its modelling using renewable energy sources. While individual methods have been well documented, there has not been a thorough investigation of these technologies. With the rising demand for environmentally friendly hydrogen production, the review will provide insights into the challenges and issues with electrolysis techniques, capital cost, water consumption, rare material utilization, electrolysis efficiency, environmental impact, and storage and security implications. The objective is to identify current control methods for efficiency improvement that can reduce costs, ensure demand, increase lifetime, and improve performance in a low-carbon energy system that can contribute to the provision of power, heat, industry, transportation, and energy storage. Issues and challenges with electrolysis techniques, capital cost, water consumption, rare material utilization, electrolysis efficiency, environmental impact, and storage and security implications have been discussed and analysed. The primary objective is to explicitly outline the present state of electrolysis technology and to provide a critical analysis of the modelling research that had been published in recent literatures. The outcome that emerges is one of qualified promise: hydrogen is well-established in particular areas, such as forklifts, and broader applications are imminent. This evaluation will bring more research improvements and a road map to aid in the commercialization of the water electrolyser for hydrogen production. All the insights revealed in this study will hopefully result in enhanced efforts in the direction of the development of advanced hydrogen electrolyser technologies towards clean, sustainable, and green energy.
•This study examines hydrogen electrolysis, its modelling and a state-of-the-art review.•Electrolysis offers a sustainable, high-purity method of producing hydrogen.•Details of hydrogen electrolysis are presented, including challenges and prospects.•Electrolysis technological issues and future suggested directions are outlined.•Advancements in hydrogen electrolysis are necessary for a renewable energy future.
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Ni doped In2O3 (NixIn2−xO3: x=0.00, 0.02, 0.04, 0.06, 0.08 and 0.10) films have been successfully prepared by a sol-gel method. All films have nanograins, cubic structures and single phase. The Ni ...unsystematically affected the film thickness and surface roughness. All films showed high transmission percentage i.e. in the range of 92–99% at wavelength more than 380 nm. All films except film with x=0.02 and 0.06 have magnetic properties. It is also found that all of the films were sensitive towards the humidity changes and can be used as a humidity sensor.
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•Zn(O,S) thin films were successfully prepared using radio frequency magnetron sputtering followed by sulfurization.•ZnS intensity peaks increase as the sulfur weight increase at a sulfurization ...temperature of 500 °C.•The grain size of the films increases as the weight of sulfur increases.•The films had increased transmittance and energy gaps after sulfurizing.
In this paper, we propose a method of incorporating sulfur on the ZnO film surface, which can effectively alter the properties of the ZnO. Through sulfurization, a ZnS cubic crystal structure is formed in the ZnO film, with the ZnS peak increasing as the sulfur weight increases. This approach may pave the way for the successful production of Zn(O,S) film which may suit as an alternative buffer layer for CIGS solar cell structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
