Pub Date : 2023-09-01DOI: 10.1051/epjap/2023230107
Mahdiyeh Karami, Salar Karim Fatah, H. Amrollahi Bioki, M. Hakimi
Zinc ferrite nanocomposites ZnxFe3-xO4 (x=0, 0.5, 0.7, 0.8, 0.9, and 1) were successfully synthesized using the sol-gel co-precipitation technique. The physicochemical properties of the resulting nanocomposites were investigated using X-ray diffraction (XRD), Rietveld refinement technique (GSASII), scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectrometry, UV/vis spectroscopy, and a vibrating sample magnetometer (VSM). The predominant phase in all of the samples was found to be ZnFe2O4 spinel, with other phases such as Fe2O3 and Fe3O4 also present. The crystallite size ranged from 6.87 to 10.88 nm, and the resulting spinel phase powder had grain sizes between 100 and 220 nm. The lattice constants and coercivity of the samples increased with increasing Zn concentration, while saturation magnetization decreased. The photocatalytic activity of the nanocomposites for the photo-degradation of methylene blue (MB) aqueous solution was investigated, and the ZnFe2O4 nanocomposites showed the highest MB degradation rate and efficiency (92%) within 60 minutes of UV and visible light irradiation. These results demonstrate the potential of ZnFe2O4 nanocomposites synthesized via the sol-gel co-precipitation technique for photocatalytic applications.
{"title":"Zinc ferrite ZnxFe3–xO4 nanocomposites as efficient photocatalysts: a study of synthesis, properties and catalytic activity","authors":"Mahdiyeh Karami, Salar Karim Fatah, H. Amrollahi Bioki, M. Hakimi","doi":"10.1051/epjap/2023230107","DOIUrl":"https://doi.org/10.1051/epjap/2023230107","url":null,"abstract":"Zinc ferrite nanocomposites ZnxFe3-xO4 (x=0, 0.5, 0.7, 0.8, 0.9, and 1) were successfully synthesized using the sol-gel co-precipitation technique. The physicochemical properties of the resulting nanocomposites were investigated using X-ray diffraction (XRD), Rietveld refinement technique (GSASII), scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectrometry, UV/vis spectroscopy, and a vibrating sample magnetometer (VSM). The predominant phase in all of the samples was found to be ZnFe2O4 spinel, with other phases such as Fe2O3 and Fe3O4 also present. The crystallite size ranged from 6.87 to 10.88 nm, and the resulting spinel phase powder had grain sizes between 100 and 220 nm. The lattice constants and coercivity of the samples increased with increasing Zn concentration, while saturation magnetization decreased. The photocatalytic activity of the nanocomposites for the photo-degradation of methylene blue (MB) aqueous solution was investigated, and the ZnFe2O4 nanocomposites showed the highest MB degradation rate and efficiency (92%) within 60 minutes of UV and visible light irradiation. These results demonstrate the potential of ZnFe2O4 nanocomposites synthesized via the sol-gel co-precipitation technique for photocatalytic applications.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114418775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The crystallization behavior and electrical performance of Y-doped Zn15Sb85 phase change material were proposed and experimental examined. The relationship between the resistance and temperature reveals that the Y dopant is able to enhancing the thermal stability (Tc～237 °C, T10～169 °C) and resistivity (Ra～105 Ω, Rc～102 Ω) of Zn15Sb85 films, which are suitable for automobile design and surface mount technology. XRD results indicate that the Y dopant could effectively inhibit grain growth and reduce grain size. Meanwhile, XPS illustrates that Y is more likely to form bonds with Sb. Further, the resistance drift index and surface roughness become small after doping Y element, which is of great benefit to improving the reliability and electrical performance of the device. Moreover, T-shaped phase change memory cells based on Y0.36(Zn15Sb85)0.64 film were also built and analyzed. The characteristic of current - voltage (I-V) and resistance - voltage (R-V) prove that the SET and RESET operations can be achieved by electric induction, implying the excellent candidate of Y-doped Zn15Sb85 material for high thermal and high reliability application.
{"title":"Influence of yttrium element on the crystallization performance of ZnSb alloy for phase change memory application","authors":"Bowen Fu, Weihua Wu, Pei Zhang, Han Gu, Xiaochen Zhou, Xiaoqin Zhu","doi":"10.1051/epjap/2023230054","DOIUrl":"https://doi.org/10.1051/epjap/2023230054","url":null,"abstract":"The crystallization behavior and electrical performance of Y-doped Zn15Sb85 phase change material were proposed and experimental examined. The relationship between the resistance and temperature reveals that the Y dopant is able to enhancing the thermal stability (Tc～237 °C, T10～169 °C) and resistivity (Ra～105 Ω, Rc～102 Ω) of Zn15Sb85 films, which are suitable for automobile design and surface mount technology. XRD results indicate that the Y dopant could effectively inhibit grain growth and reduce grain size. Meanwhile, XPS illustrates that Y is more likely to form bonds with Sb. Further, the resistance drift index and surface roughness become small after doping Y element, which is of great benefit to improving the reliability and electrical performance of the device. Moreover, T-shaped phase change memory cells based on Y0.36(Zn15Sb85)0.64 film were also built and analyzed. The characteristic of current - voltage (I-V) and resistance - voltage (R-V) prove that the SET and RESET operations can be achieved by electric induction, implying the excellent candidate of Y-doped Zn15Sb85 material for high thermal and high reliability application.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129743645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-10DOI: 10.1051/epjap/2023230032
Cheng Chen, Yuting Wang, Keyu An, Zhongyuan Ren
Acoustophoresis separation technique has attracted great attention due to its superior properties, such as biocompatibility, non-contact, label-free and high-efficiency. In this paper, separation of particles based on motion modes via tilted-angle standing surface acoustic wave (TaSSAW) driven by a unidirectional transducer is developed. It’s verified that the designed electrode width controlled unidirectional transducers are effective to improve the acoustic wave utilization rate and increase the acoustic radiation force. The results show that when the density and compressibility of the particles are close to those of the fluid and the particle shape is close to spherical, the influences of fluid viscosity and particle shape on the acoustic radiation force are negligible. It’s found that in the TaSSAW system the motion modes of the particles are divided into locked mode and drift mode, and they depend on the fluid velocity, acoustic field intensity and title angle. polystyrene (PS) particles with radii of 4 and 5 μm are separated based on the differences of motion modes. For further smaller size difference (4.5 and 5μm) particles, the separation is also realized successfully by making particles move in the same drift mode. The proposed TaSSAW system has broad application prospects in biology and chemistry.
{"title":"Acoustophoresis Separation of Particles Based on Motion Modes via Tilted-Angle Standing Surface Acoustic Wave Driven by a Unidirectional Transducer","authors":"Cheng Chen, Yuting Wang, Keyu An, Zhongyuan Ren","doi":"10.1051/epjap/2023230032","DOIUrl":"https://doi.org/10.1051/epjap/2023230032","url":null,"abstract":"Acoustophoresis separation technique has attracted great attention due to its superior properties, such as biocompatibility, non-contact, label-free and high-efficiency. In this paper, separation of particles based on motion modes via tilted-angle standing surface acoustic wave (TaSSAW) driven by a unidirectional transducer is developed. It’s verified that the designed electrode width controlled unidirectional transducers are effective to improve the acoustic wave utilization rate and increase the acoustic radiation force. The results show that when the density and compressibility of the particles are close to those of the fluid and the particle shape is close to spherical, the influences of fluid viscosity and particle shape on the acoustic radiation force are negligible. It’s found that in the TaSSAW system the motion modes of the particles are divided into locked mode and drift mode, and they depend on the fluid velocity, acoustic field intensity and title angle. polystyrene (PS) particles with radii of 4 and 5 μm are separated based on the differences of motion modes. For further smaller size difference (4.5 and 5μm) particles, the separation is also realized successfully by making particles move in the same drift mode. The proposed TaSSAW system has broad application prospects in biology and chemistry.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125202483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1051/epjap/2023230106
Dongxuan Zhang, Fan Bu, Yulei Zhao, Z. Fang, Feng Liu
Ionic wind produced by high voltage discharge has been proved as a promising technique in heat dissipation, food drying, electrostatic precipitation and air propulsion. On the other hand, the low wind velocity and the low energy efficiency of the ionic wind generators limit their performance in practical industrial applications. To improve this, a single needle-net electrode structure ionic wind generator driven by positive DC voltage is constructed and the effects of the applied voltage and the needle-net distance on the discharge characteristics have been investigated. The results show that with the increase of the applied voltage from 4 kV to 11 kV, the discharge shows four stages, burst pulse, streamer corona, glow corona and spark discharge, and the wind velocity increases monotonously and reach 1.90 m/s at 11 kV. At the same applied voltage, the shorter needle-net distance leads to the larger wind velocity. At 15 mm needle-net distance, the needle-net electrode structure ionic wind generator shows a maximum energy efficiency value of 2.19%. A metal circular plate is attached on the needle electrode to enhance the electric field in discharge spacing. It is found that the wind velocity and energy efficiency can be improved from 1.90 m/s to 2.35 m/s, and 1.87% to 3.14%, at same applied voltage and needle-net distance. The cooling experiment shows that the ionic wind generator with metal circular plate needle-net electrode has better heat dissipation effect.
{"title":"Ionic wind velocity and energy efficiency improvement in needle-net ionic wind generator by electrical field optimization","authors":"Dongxuan Zhang, Fan Bu, Yulei Zhao, Z. Fang, Feng Liu","doi":"10.1051/epjap/2023230106","DOIUrl":"https://doi.org/10.1051/epjap/2023230106","url":null,"abstract":"Ionic wind produced by high voltage discharge has been proved as a promising technique in heat dissipation, food drying, electrostatic precipitation and air propulsion. On the other hand, the low wind velocity and the low energy efficiency of the ionic wind generators limit their performance in practical industrial applications. To improve this, a single needle-net electrode structure ionic wind generator driven by positive DC voltage is constructed and the effects of the applied voltage and the needle-net distance on the discharge characteristics have been investigated. The results show that with the increase of the applied voltage from 4 kV to 11 kV, the discharge shows four stages, burst pulse, streamer corona, glow corona and spark discharge, and the wind velocity increases monotonously and reach 1.90 m/s at 11 kV. At the same applied voltage, the shorter needle-net distance leads to the larger wind velocity. At 15 mm needle-net distance, the needle-net electrode structure ionic wind generator shows a maximum energy efficiency value of 2.19%. A metal circular plate is attached on the needle electrode to enhance the electric field in discharge spacing. It is found that the wind velocity and energy efficiency can be improved from 1.90 m/s to 2.35 m/s, and 1.87% to 3.14%, at same applied voltage and needle-net distance. The cooling experiment shows that the ionic wind generator with metal circular plate needle-net electrode has better heat dissipation effect.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123296621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-03DOI: 10.1051/epjap/2023230074
D. Saha, Sang Yeol Lee
Electron conduction mechanisms in CoFeB (0.8-10 nm)/MgO (3nm)/CoFeB (4.2 nm) magnetic tunnel junctions (MTJs) have been investigated in detail. A clear crossover from direct tunnelling to trap assisted Fowler Nordheim (FN) tunneling is observed with increasing bias voltage in all the pristine MTJs. In contrast, FN-like tunneling is completely suppressed in vacuum annealed MTJs, which plausibly indicates diffused interfaces and enhanced trap state density in MgO barrier. In annealed MTJs, beyond the direct tunneling regime, bulk-limited Pool Frenkel emission followed by interface-limited Schottky emission are found to be the dominant transport mechanisms. Simulations of tunnel current density J (V) and differential conductance (dJ/dV) of MTJs have been carried out using Simmons (symmetric rectangular barrier) and Brinkman (asymmetric trapezoidal barrier) model, which provides valuable insights on the barrier height and interface property at the MgO/CoFeB interface. Results of this study might be helpful to further improve CoFeB/MgO based MTJs for efficient implementation in sensors and memory devices.
{"title":"Crossover from direct to trap assisted Fowler Nordheim (FN) tunneling in CoFeB/MgO/CoFeB magnetic tunnel junctions","authors":"D. Saha, Sang Yeol Lee","doi":"10.1051/epjap/2023230074","DOIUrl":"https://doi.org/10.1051/epjap/2023230074","url":null,"abstract":"Electron conduction mechanisms in CoFeB (0.8-10 nm)/MgO (3nm)/CoFeB (4.2 nm) magnetic tunnel junctions (MTJs) have been investigated in detail. A clear crossover from direct tunnelling to trap assisted Fowler Nordheim (FN) tunneling is observed with increasing bias voltage in all the pristine MTJs. In contrast, FN-like tunneling is completely suppressed in vacuum annealed MTJs, which plausibly indicates diffused interfaces and enhanced trap state density in MgO barrier. In annealed MTJs, beyond the direct tunneling regime, bulk-limited Pool Frenkel emission followed by interface-limited Schottky emission are found to be the dominant transport mechanisms. Simulations of tunnel current density J (V) and differential conductance (dJ/dV) of MTJs have been carried out using Simmons (symmetric rectangular barrier) and Brinkman (asymmetric trapezoidal barrier) model, which provides valuable insights on the barrier height and interface property at the MgO/CoFeB interface. Results of this study might be helpful to further improve CoFeB/MgO based MTJs for efficient implementation in sensors and memory devices.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130317726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-19DOI: 10.1051/epjap/2023230094
Chokalingam Saravanan, P. Balaji Bhargav, V. N, Nafis Ahmed, A. K.,, Balaji C
Mn-doped BiFeO3 (BFO) thin films were prepared on glass substrates using a simple spin coating method, and their structural and optical properties were analyzed. The X-ray diffraction pattern of Mn-doped BFO confirmed the presence of rhombohedral distorted perovskite structure, while FTIR analysis detected the Bi-O and Fe-O bonds in the perovskite structure. The XPS spectra of the Mn-doped BFO thin film provided information on the valence states of Bi, Fe, and Mn based on their respective binding energies. The UV-visible-NIR spectra revealed that the optical band gap of the pristine BFO was 2.17 eV, while that of Mn-doped BFO was 1.65 eV, which is optimum for solar cell absorber layer applications. The decreasing pattern suggests effective Mn doping of BFO.
{"title":"Bandgap tuning of Mn-doped of BiFeO3 thin films for Photovoltaic Application","authors":"Chokalingam Saravanan, P. Balaji Bhargav, V. N, Nafis Ahmed, A. K.,, Balaji C","doi":"10.1051/epjap/2023230094","DOIUrl":"https://doi.org/10.1051/epjap/2023230094","url":null,"abstract":"Mn-doped BiFeO3 (BFO) thin films were prepared on glass substrates using a simple spin coating method, and their structural and optical properties were analyzed. The X-ray diffraction pattern of Mn-doped BFO confirmed the presence of rhombohedral distorted perovskite structure, while FTIR analysis detected the Bi-O and Fe-O bonds in the perovskite structure. The XPS spectra of the Mn-doped BFO thin film provided information on the valence states of Bi, Fe, and Mn based on their respective binding energies. The UV-visible-NIR spectra revealed that the optical band gap of the pristine BFO was 2.17 eV, while that of Mn-doped BFO was 1.65 eV, which is optimum for solar cell absorber layer applications. The decreasing pattern suggests effective Mn doping of BFO.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122455915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.1051/epjap/2023230029
Junxiang Zhao, Ziyan Yu, Jiawei Chen, Yupeng Su, Jiafu Wang, N. Yu
We constructed the GeSe/SnTe van der Waals (vdW) two-dimensional (2D) heterostructure with the use of the first-principles calculation, which has a 0.481 eV indirect bandgap and the type-II band alignment. The GeSe/SnTe heterostructure has superior wide range light absorption with the maximum value of 8.69 105 cm-1, and the heterostructure also exhibits anisotropic carrier mobilities with the maximum value of 8.36 103 cm2 V-1 s-1. By strain engineering, the band structure of GeSe/SnTe heterostructure is able to be modulated effectively. Moreover, by applying biaxial strain, we can greatly enhance the photoelectric conversion efficiency (PCE) of GeSe/SnTe heterostructure, which can reach 15.29% under 4% tensile strain. Our calculation results reveal that the GeSe/SnTe heterostructure can be considered to apply in the nextgeneration solar cells.
{"title":"A type-II GeSe/SnTe heterostructure with \u0000superior optical absorption and strain tunable \u0000photovoltaic properties","authors":"Junxiang Zhao, Ziyan Yu, Jiawei Chen, Yupeng Su, Jiafu Wang, N. Yu","doi":"10.1051/epjap/2023230029","DOIUrl":"https://doi.org/10.1051/epjap/2023230029","url":null,"abstract":"We constructed the GeSe/SnTe van der Waals (vdW) two-dimensional (2D) \u0000heterostructure with the use of the first-principles calculation, which has a 0.481 eV indirect bandgap and the type-II band alignment. The GeSe/SnTe heterostructure has superior wide range light absorption with the maximum value of 8.69 105 cm-1, and the heterostructure also exhibits anisotropic carrier mobilities with the maximum value of 8.36 103 cm2 V-1 s-1. By strain engineering, the band structure of GeSe/SnTe heterostructure is able to be modulated effectively. Moreover, by applying biaxial strain, we can greatly enhance the photoelectric conversion efficiency (PCE) of GeSe/SnTe heterostructure, which can reach 15.29% under 4% tensile strain. Our calculation results reveal that the GeSe/SnTe heterostructure can be considered to apply in the nextgeneration solar cells.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"554 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121421049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-21DOI: 10.1051/epjap/2023230035
Alexander Y Ilyushechkin, San Shwe Hla, L. Schoeman
During thermochemical processing of biosolids in sewage sludge, different forms of phosphor-containing compounds are generated in biosolid chars (biochars). This paper describes how biochar-processing conditions affect the mineral compounds formed under pyrolysis, gasification and combustion of biosolids, and the key factors that influence the kinetics of phase formation. Our results show identified phase transformations through experiments in a laboratory tube furnace followed by X-ray diffraction analysis. Laboratory processing samples were verified and in situ phase transformations were observed through a synchrotron powder diffraction study. It was found that under a neutral atmosphere, crystalline oxide phases formed at lower temperatures and much faster than iron phosphide formed, while gasification and combustion conditions led to the formation of crystalline phases in phosphate forms. These forms of phosphor compounds in by-products of biosolids thermochemical treatment can be used as agricultural fertilizers.
{"title":"Transformation of mineral matter during pyrolysis, gasification and combustion of biosolid chars","authors":"Alexander Y Ilyushechkin, San Shwe Hla, L. Schoeman","doi":"10.1051/epjap/2023230035","DOIUrl":"https://doi.org/10.1051/epjap/2023230035","url":null,"abstract":"During thermochemical processing of biosolids in sewage sludge, different forms of phosphor-containing compounds are generated in biosolid chars (biochars). This paper describes how biochar-processing conditions affect the mineral compounds formed under pyrolysis, gasification and combustion of biosolids, and the key factors that influence the kinetics of phase formation. \u0000Our results show identified phase transformations through experiments in a laboratory tube furnace followed by X-ray diffraction analysis. Laboratory processing samples were verified and in situ phase transformations were observed through a synchrotron powder diffraction study. \u0000It was found that under a neutral atmosphere, crystalline oxide phases formed at lower temperatures and much faster than iron phosphide formed, while gasification and combustion conditions led to the formation of crystalline phases in phosphate forms. These forms of phosphor compounds in by-products of biosolids thermochemical treatment can be used as agricultural fertilizers. \u0000","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127314050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-08DOI: 10.1051/epjap/2023220300
Taghourt Abdeldjalil, S. Aklouche-benouaguef, B. Zeghmati
In this paper we present a numerical study of an unsteady Al2O3 water nanofluid mixed convection in a differentiated square ventilated cavity. The routes from steady-state to chaotic mixed convection state have been also studied for a constant Reynolds Number (Re), Re=50 and Richardson number (Ri) ranging from Ri=40 to Ri=150. The governing equations are solved using an implicit finite-volume scheme and TDMA algorithm. Results are presented through streamlines, isotherms, mean temperature, average Nusselt number, pressure drop…. It is observed that the average Nusselt number and the mean cavity temperature values are all the higher as the Ri number is great. The pressure drop slightly decreases as Ri number increases. The fully chaotic flow regime is reached after three stages. The first stage is similar to the Ruelle-Takens-Newhouse scenario. At the end of this stage, apparition of periodicity interrupted the development of a full chaos initiating the second stage of the route to chaos where another series of three supercritical Hopf type bifurcations and a period doubling bifurcation take place. The third stage starts by the emergence of intermittencies which interrupts the apparition of a full chaotic flow. A complete chaos is achieved at the end of this third stage.
{"title":"A three stages transition into chaos for mixed convection nanofluid inside a differentially-heated square ventilated cavity","authors":"Taghourt Abdeldjalil, S. Aklouche-benouaguef, B. Zeghmati","doi":"10.1051/epjap/2023220300","DOIUrl":"https://doi.org/10.1051/epjap/2023220300","url":null,"abstract":"In this paper we present a numerical study of an unsteady Al2O3 water nanofluid mixed convection in a differentiated square ventilated cavity. The routes from steady-state to chaotic mixed convection state have been also studied for a constant Reynolds Number (Re), Re=50 and Richardson number (Ri) ranging from Ri=40 to Ri=150. The governing equations are solved using an implicit finite-volume scheme and TDMA algorithm. Results are presented through streamlines, isotherms, mean temperature, average Nusselt number, pressure drop…. It is observed that the average Nusselt number and the mean cavity temperature values are all the higher as the Ri number is great. The pressure drop slightly decreases as Ri number increases. The fully chaotic flow regime is reached after three stages. The first stage is similar to the Ruelle-Takens-Newhouse scenario. At the end of this stage, apparition of periodicity interrupted the development of a full chaos initiating the second stage of the route to chaos where another series of three supercritical Hopf type bifurcations and a period doubling bifurcation take place. The third stage starts by the emergence of intermittencies which interrupts the apparition of a full chaotic flow. A complete chaos is achieved at the end of this third stage.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123927692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-27DOI: 10.1051/epjap/2023230018
K. Hoummada, F. Dahlem, F. Panciera, É. Bustarret, C. Marcenat, D. Débarre, Y. Amraoui, D. Mangelinck, L. Tetard, H. Oughaddou, A. Kara, Y. Dappe, N. Rochdi
Three dimensional distributions of boron atoms incorporated into crystalline silicon (3-9 B % at.) well above the solubility limit are measured by atom probe tomography (APT). Samples have been prepared either by gas immersion laser doping (GILD) or by implantation followed by laser annealing (Pulsed Laser Induced Epitaxy: PLIE). GILD and PLIE silicon samples show superconducting properties at low temperature thanks to the achieved high doping level. In both cases, boron atoms are found to be randomly distributed within the silicon as revealed by statistical distribution analysis. No cluster or precipitate are detected, which can be related to the high speed of recrystallization of the Si:B alloy. A sharp 2D interface between the doped silicon region and the undoped substrate is also observed, characterizing a Si:B/Si epitaxy. Finally, the variation of the evaporation field is investigated in both materials by considering either the silicon charge states ratio or the variation of the total voltage applied during the analysis of the Si:B layer.
{"title":"Analysis of superconducting silicon epilayers by atom probe tomography: Composition and Evaporation field","authors":"K. Hoummada, F. Dahlem, F. Panciera, É. Bustarret, C. Marcenat, D. Débarre, Y. Amraoui, D. Mangelinck, L. Tetard, H. Oughaddou, A. Kara, Y. Dappe, N. Rochdi","doi":"10.1051/epjap/2023230018","DOIUrl":"https://doi.org/10.1051/epjap/2023230018","url":null,"abstract":"Three dimensional distributions of boron atoms incorporated into crystalline silicon (3-9 B % at.) well above the solubility limit are measured by atom probe tomography (APT). Samples have been prepared either by gas immersion laser doping (GILD) or by implantation followed by laser annealing (Pulsed Laser Induced Epitaxy: PLIE). GILD and PLIE silicon samples show superconducting properties at low temperature thanks to the achieved high doping level. In both cases, boron atoms are found to be randomly distributed within the silicon as revealed by statistical distribution analysis. No cluster or precipitate are detected, which can be related to the high speed of recrystallization of the Si:B alloy. A sharp 2D interface between the doped silicon region and the undoped substrate is also observed, characterizing a Si:B/Si epitaxy. Finally, the variation of the evaporation field is investigated in both materials by considering either the silicon charge states ratio or the variation of the total voltage applied during the analysis of the Si:B layer.","PeriodicalId":301303,"journal":{"name":"The European Physical Journal Applied Physics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127582155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：