Pub Date : 2025-02-16DOI: 10.1016/j.jcrysgro.2025.128104
Bin Han , Dianchun Ju , Zhuo Chen , Yunjie Bao , Yingying Li , Qin Yan , Yuxia Liu , Chunyu Chen
Titanium dioxide nanoparticles (TiO2 NPs) have garnered considerable attention within the materials science community due to their superior availability, high photocatalytic activity, remarkable thermal stability, and cost-effectiveness. Recently, a growing interest has emerged in their potential applications within scientific research. Therefore, the development of more efficient and controllable preparation methods has been concentrated in current studies. This study uses deep eutectic solvents (DESs) as solvents and structure-directing agents to provide a gentle and environmentally friendly process for the controlled synthesis of TiO2 NPs. Furthermore, it examines their photocatalytic degradation performance on dye wastewater under full-spectrum light sources. The findings reveal that by introducing TiCl4-DESs in a mass ratio of 1:10 in a hydrolytic solution of PEG-H2O with a mass ratio of 1:1, and subsequently, calcining the mixture at 550 ℃ in a muffle furnace, uniform spherical pure anatase–type TiO2 NPs with good dispersion and an average particle size of approximately 14.01 nm can be obtained. After 60 min of exposure to a full-spectrum light source, the removal rate of methylene blue reached 99.2 %. After 180 min, the degradation rates of rhodamine B and methyl orange were found to be 97.0 % and 80.7 %, respectively. These results demonstrate that the application of DESs facilitates the green and mild modulation of the nanostructures and grain sizes of TiO2 NPs, effectively enhancing their photocatalytic activity.
{"title":"Controllable preparation of TiO2 nanoparticles using deep eutectic solvents and their photocatalytic degradation of dyeing wastewater","authors":"Bin Han , Dianchun Ju , Zhuo Chen , Yunjie Bao , Yingying Li , Qin Yan , Yuxia Liu , Chunyu Chen","doi":"10.1016/j.jcrysgro.2025.128104","DOIUrl":"10.1016/j.jcrysgro.2025.128104","url":null,"abstract":"<div><div>Titanium dioxide nanoparticles (TiO<sub>2</sub> NPs) have garnered considerable attention within the materials science community due to their superior availability, high photocatalytic activity, remarkable thermal stability, and cost-effectiveness. Recently, a growing interest has emerged in their potential applications within scientific research. Therefore, the development of more efficient and controllable preparation methods has been concentrated in current studies. This study uses deep eutectic solvents (DESs) as solvents and structure-directing agents to provide a gentle and environmentally friendly process for the controlled synthesis of TiO<sub>2</sub> NPs. Furthermore, it examines their photocatalytic degradation performance on dye wastewater under full-spectrum light sources. The findings reveal that by introducing TiCl<sub>4</sub>-DESs in a mass ratio of 1:10 in a hydrolytic solution of PEG-H<sub>2</sub>O with a mass ratio of 1:1, and subsequently, calcining the mixture at 550 ℃ in a muffle furnace, uniform spherical pure anatase–type TiO<sub>2</sub> NPs with good dispersion and an average particle size of approximately 14.01 nm can be obtained. After 60 min of exposure to a full-spectrum light source, the removal rate of methylene blue reached 99.2 %. After 180 min, the degradation rates of rhodamine B and methyl orange were found to be 97.0 % and 80.7 %, respectively. These results demonstrate that the application of DESs facilitates the green and mild modulation of the nanostructures and grain sizes of TiO<sub>2</sub> NPs, effectively enhancing their photocatalytic activity.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"656 ","pages":"Article 128104"},"PeriodicalIF":1.7,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.jcrysgro.2025.128094
A. Farhadizadeh , J. Salamania , M.A. Sortica , D. Primetzhofer , M. Odén
We explore the growth of high-quality epitaxial NbN films on Al2O3 (0006) (Sapphire c-plane). The study investigates the structural and electrical characteristics as a function of film thickness. Pole figures analyses reveal the formation of epitaxial growth with two sets of domains, attributed to the differing symmetries of the cubic NbN and rhombohedral Sapphire. We identified the epitaxial relationship as || . Medium and high-resolution X-ray diffractometry shows clear Kiessig fringes, which become asymmetric for thicknesses greater than 18 nm. The asymmetry is inferred to arise from relaxed domains dispersed in the film in low concentrations near the substrate-film interface and then become more widespread with increased thickness based on dynamical XRD simulation and dark field transition electron microscopy. All films display a rocking curve consisting of an intense sharp peak, accompanied by a broader peak that intensifies as the thickness increases. The sharp peak reflects a highly ordered, long-range correlated structure within NbN, while the broadened peak indicates regions of slightly misoriented NbN, likely related to strain relaxation in local domains. X-ray reflectivity indicates that the mass density is higher than bulk NbN for the thinnest films, it decreases as the films grow thicker and stabilizes at 7.8 g·cm−3 for films thicker than ∼ 70 nm. As thickness increases, the lattice constant decreases due to relaxation, which also impacts the electrical resistivity. The strained films exhibit slightly lower resistivity than the relaxed films, likely due to the higher crystallinity of the thinner films.
{"title":"Structure evolution during growth of epitaxial NbN films on Al2O3 (0006) deposited by magnetron sputtering and its impact on electrical properties","authors":"A. Farhadizadeh , J. Salamania , M.A. Sortica , D. Primetzhofer , M. Odén","doi":"10.1016/j.jcrysgro.2025.128094","DOIUrl":"10.1016/j.jcrysgro.2025.128094","url":null,"abstract":"<div><div>We explore the growth of high-quality epitaxial NbN films on Al<sub>2</sub>O<sub>3</sub> (0006) (Sapphire c-plane). The study investigates the structural and electrical characteristics as a function of film thickness. Pole figures analyses reveal the formation of epitaxial growth with two sets of domains, attributed to the differing symmetries of the cubic NbN and rhombohedral Sapphire. We identified the epitaxial relationship as <span><math><mrow><mtext>(0001)[2</mtext><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mtext>0]</mtext></mrow></math></span> <!-->||<!--> <span><math><mrow><mtext>(111)[1</mtext><mover><mrow><mtext>1</mtext></mrow><mrow><mo>¯</mo></mrow></mover><mtext>0]</mtext></mrow></math></span>. Medium and high-resolution X-ray diffractometry shows clear Kiessig fringes, which become asymmetric for thicknesses greater than 18 nm. The asymmetry is inferred to arise from relaxed domains dispersed in the film in low concentrations near the substrate-film interface and then become more widespread with increased thickness based on dynamical XRD simulation and dark field transition electron microscopy. All films display a rocking curve consisting of an intense sharp peak, accompanied by a broader peak that intensifies as the thickness increases. The sharp peak reflects a highly ordered, long-range correlated structure within NbN, while the broadened peak indicates regions of slightly misoriented NbN, likely related to strain relaxation in local domains. X-ray reflectivity indicates that the mass density is higher than bulk NbN for the thinnest films, it decreases as the films grow thicker and stabilizes at 7.8 g·cm<sup>−3</sup> for films thicker than ∼ 70 nm. As thickness increases, the lattice constant decreases due to relaxation, which also impacts the electrical resistivity. The strained films exhibit slightly lower resistivity than the relaxed films, likely due to the higher crystallinity of the thinner films.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"656 ","pages":"Article 128094"},"PeriodicalIF":1.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the effect of certain transition metal cations (Cr3+, Ni2+, Co2+ and Mn2+) on the hydrothermal synthesis of barium hexaferrite was investigated. It was found that the addition of Co2+ and Mn2+ significantly promotes the formation of the hexaferrite phase. In other cases, the dominant product of the reaction was the non-magnetic ferrihydrite. The mechanism by which hexaferrite forms in the presence of Co2+ or Mn2+ was discussed. The hexaferrites obtained in this work were nanoplates with a thickness of no more than 20 nm and a diameter ranging from 80 to 400 nm. These powders had a low saturation magnetization (<20 emu/g) and coercivity (<450 Oe). Although the magnetism of these hexaferrite nanoplates is relatively weak, they can still be manipulated by external magnetic field and could be used to prepare anisotropic hexaferrite materials. Pierre Muller
{"title":"The effect of transition metal ions on the phase formation during the hydrothermal synthesis of barium hexaferrite","authors":"A.Yu. Mironovich , V.G. Kostishin , G.A. Skorlupin , E.S. Savchenko , A.I. Ril","doi":"10.1016/j.jcrysgro.2025.128095","DOIUrl":"10.1016/j.jcrysgro.2025.128095","url":null,"abstract":"<div><div>In this study, the effect of certain transition metal cations (Cr<sup>3+</sup>, Ni<sup>2+</sup>, Co<sup>2+</sup> and Mn<sup>2+</sup>) on the hydrothermal synthesis of barium hexaferrite was investigated. It was found that the addition of Co<sup>2+</sup> and Mn<sup>2+</sup> significantly promotes the formation of the hexaferrite phase. In other cases, the dominant product of the reaction was the non-magnetic ferrihydrite. The mechanism by which hexaferrite forms in the presence of Co<sup>2+</sup> or Mn<sup>2+</sup> was discussed. The hexaferrites obtained in this work were nanoplates with a thickness of no more than 20 nm and a diameter ranging from 80 to 400 nm. These powders had a low saturation magnetization (<20 emu/g) and coercivity (<450 Oe). Although the magnetism of these hexaferrite nanoplates is relatively weak, they can still be manipulated by external magnetic field and could be used to prepare anisotropic hexaferrite materials. Pierre Muller</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"656 ","pages":"Article 128095"},"PeriodicalIF":1.7,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-08DOI: 10.1016/j.jcrysgro.2025.128096
Lioudmila V. Sorokina , Azadeh Amiri , Pavel L. Rehak , Alireza Ghorbani , Abhijit H. Phakatkar , Petr Král , Tolou Shokuhfar , Reza Shahbazian-Yassar
Aberrant cholesterol crystallization has implications in the development of numerous pathologies. However, current imaging methods rely on extensive sample preparation and static conditions, unable to capture real-time transformations. This study utilized in-situ graphene liquid cell transmission electron microscopy to capture nanoscale events of cholesterol monohydrate (ChM) nucleation and growth. The results revealed ChM triclinic forms through a combination of non-classical and classical modes, specifically, a modified Stranski − Krastanov mechanism. ChM triclinic nucleates from an amorphous precursor, which grows on triclinic surfaces as an epilayer. These epilayers coalesce into 2D layers formed along a preferred lattice plane, enabling 3D growth. Molecular dynamics simulations revealed that the amorphous to crystalline transition occurs via the self-assembly of small clusters, interconnected by filaments, which regrow into bilayers with exposed polar groups. These superstructures adsorb on the surfaces of crystalline cholesterol, form islands, which spread and form nuclei of a new bilayer. This study underscores the significance of homoepitaxy in ChM growth and may provide additional insights into biologically relevant processes, such as ChM nucleation on lipid droplets. Overall, this study lays the foundation for investigating the mechanisms of ChM growth from solution in real-time and on the nanoscale.
{"title":"Real-time nanoscale visualization of cholesterol monohydrate nucleation and growth","authors":"Lioudmila V. Sorokina , Azadeh Amiri , Pavel L. Rehak , Alireza Ghorbani , Abhijit H. Phakatkar , Petr Král , Tolou Shokuhfar , Reza Shahbazian-Yassar","doi":"10.1016/j.jcrysgro.2025.128096","DOIUrl":"10.1016/j.jcrysgro.2025.128096","url":null,"abstract":"<div><div>Aberrant cholesterol crystallization has implications in the development of numerous pathologies. However, current imaging methods rely on extensive sample preparation and static conditions, unable to capture real-time transformations. This study utilized <em>in-situ</em> graphene liquid cell transmission electron microscopy to capture nanoscale events of cholesterol monohydrate (ChM) nucleation and growth. The results revealed ChM triclinic forms through a combination of non-classical and classical modes, specifically, a modified Stranski − Krastanov mechanism. ChM triclinic nucleates from an amorphous precursor, which grows on triclinic surfaces as an epilayer. These epilayers coalesce into 2D layers formed along a preferred lattice plane, enabling 3D growth. Molecular dynamics simulations revealed that the amorphous to crystalline transition occurs via the self-assembly of small clusters, interconnected by filaments, which regrow into bilayers with exposed polar groups. These superstructures adsorb on the surfaces of crystalline cholesterol, form islands, which spread and form nuclei of a new bilayer. This study underscores the significance of homoepitaxy in ChM growth and may provide additional insights into biologically relevant processes, such as ChM nucleation on lipid droplets. Overall, this study lays the foundation for investigating the mechanisms of ChM growth from solution in real-time and on the nanoscale.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"655 ","pages":"Article 128096"},"PeriodicalIF":1.7,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-06DOI: 10.1016/j.jcrysgro.2025.128093
Kang Han , Dandan Gong , Chengwei Du , Lijuan Zhang , Lu Wang , Jing Lian , Aniruddha Majumder , Jie Lu
The influence of 2,2,6,6-Tetramethylpiperidinooxy (TEMPO) cellulose nanofibers (TCNF) on the nucleation and growth of sulfathiazole (STZ) crystals is uncovered, aiding in the precise control of drug crystal morphology. To elucidate the mechanism by which TCNF regulates the nucleation and growth of STZ crystals, cooling crystallization experiments and molecular simulations were conducted. Initially, the crystal forms of STZ in pure water were determined. Subsequently, crystallization experiments with the addition of TCNF were conducted. The experiments aimed to investigate their effects on crystal form and crystal habits. The results revealed that a pure Form III was obtained due to the hydrogen bonding interactions on the surface of TCNF. Molecular simulations helped better explain the influence on specific crystal faces. This study indicates that the influence of TCNF on the characteristics of STZ crystals is mediated through interaction with the z-axis crystal facets, leading to the formation of block-shaped crystals. In addition, the higher concentration of TCNF forms a local closed space, resulting in blocked mobility, allowing STZ molecules in the solution to grow at the defects of STZ crystallization.
{"title":"Crystallization and growth control of sulfathiazole using 2,2,6,6-tetramethylpiperidinooxy cellulose nanofibers gel","authors":"Kang Han , Dandan Gong , Chengwei Du , Lijuan Zhang , Lu Wang , Jing Lian , Aniruddha Majumder , Jie Lu","doi":"10.1016/j.jcrysgro.2025.128093","DOIUrl":"10.1016/j.jcrysgro.2025.128093","url":null,"abstract":"<div><div>The influence of 2,2,6,6-Tetramethylpiperidinooxy (TEMPO) cellulose nanofibers (TCNF) on the nucleation and growth of sulfathiazole (STZ) crystals is uncovered, aiding in the precise control of drug crystal morphology. To elucidate the mechanism by which TCNF regulates the nucleation and growth of STZ crystals, cooling crystallization experiments and molecular simulations were conducted. Initially, the crystal forms of STZ in pure water were determined. Subsequently, crystallization experiments with the addition of TCNF were conducted. The experiments aimed to investigate their effects on crystal form and crystal habits. The results revealed that a pure Form III was obtained due to the hydrogen bonding interactions on the surface of TCNF. Molecular simulations helped better explain the influence on specific crystal faces. This study indicates that the influence of TCNF on the characteristics of STZ crystals is mediated through interaction with the z-axis crystal facets, leading to the formation of block-shaped crystals. In addition, the higher concentration of TCNF forms a local closed space, resulting in blocked mobility, allowing STZ molecules in the solution to grow at the defects of STZ crystallization.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"655 ","pages":"Article 128093"},"PeriodicalIF":1.7,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gallium nitride (GaN) films have been grown on Si (111) substrates with low-temperature GaN as a buffer layer using a newly developed Radical Enhanced Metal Organic Chemical Vapor Deposition (REMOCVD) system. This REMOCVD system has three features; (1) the application of very high-frequency (VHF) of 100 MHz to increase the plasma density, (2) the introduction of H2 gas together with N2 gas in the plasma discharge region to generate active NHx radical species in addition to nitrogen radicals, and (3) the radical supply under remote plasma arrangement with suppressed charged ions and photons by employing a Faraday‘s cage. Using this new system, we have studied the homoepitaxial growth of GaN. It was found that high-quality crystals can be grown by REMOCVD at temperatures of 800 °C lower than those of MOCVD. However, the buffer layer is necessary for the heteroepitaxial growth of GaN on Si. In the present study, the low-temperature GaN (LT-GaN) grown at 600 °C was used as the buffer layer. The growth conditions such as the effect of N-termination of Si and the effect of thickness of LT-GaN as a buffer layer were optimized. The surface morphology and the cleaved cross-sectional view of GaN grown on Si substrates were studied by scanning electron microscopy (SEM). The crystal quality of GaN grown on Si substrates was evaluated by X-ray diffraction (XRD). The epitaxial growth of GaN on Si (111) substrates was achieved by the REMOCVD method with a growth rate of approximately 0.6 µm/h at a low temperature of 800 ℃. The present REMOCVD system is a very promising method for the growth of GaN on Si at relatively low temperatures without using toxic and costly ammonia gas.
{"title":"Radical enhanced growth of GaN on Si with the buffer layer of GaN at a low temperature of 600 °C","authors":"Swathy Jayaprasad, Arun Kumar Dhasiyan, Naohiro Shimizu, Osamu Oda, Hiromasa Tanaka, Masaru Hori","doi":"10.1016/j.jcrysgro.2025.128089","DOIUrl":"10.1016/j.jcrysgro.2025.128089","url":null,"abstract":"<div><div>Gallium nitride (GaN) films have been grown on Si (111) substrates with low-temperature GaN as a buffer layer using a newly developed Radical Enhanced Metal Organic Chemical Vapor Deposition (REMOCVD) system. This REMOCVD system has three features; (1) the application of very high-frequency (VHF) of 100 MHz to increase the plasma density, (2) the introduction of H<sub>2</sub> gas together with N<sub>2</sub> gas in the plasma discharge region to generate active NH<sub>x</sub> radical species in addition to nitrogen radicals, and (3) the radical supply under remote plasma arrangement with suppressed charged ions and photons by employing a Faraday‘s cage. Using this new system, we have studied the homoepitaxial growth of GaN. It was found that high-quality crystals can be grown by REMOCVD at temperatures of 800 °C lower than those of MOCVD. However, the buffer layer is necessary for the heteroepitaxial growth of GaN on Si. In the present study, the low-temperature GaN (LT-GaN) grown at 600 °C was used as the buffer layer. The growth conditions such as the effect of N-termination of Si and the effect of thickness of LT-GaN as a buffer layer were optimized. The surface morphology and the cleaved cross-sectional view of GaN grown on Si substrates were studied by scanning electron microscopy (SEM). The crystal quality of GaN grown on Si substrates was evaluated by X-ray diffraction (XRD). The epitaxial growth of GaN on Si (111) substrates was achieved by the REMOCVD method with a growth rate of approximately 0.6 µm/h at a low temperature of 800 ℃. The present REMOCVD system is a very promising method for the growth of GaN on Si at relatively low temperatures without using toxic and costly ammonia gas.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"656 ","pages":"Article 128089"},"PeriodicalIF":1.7,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have investigated the effect of the crystallographic orientation of B-doped Si (p-Si) crystalline targets on the activation temperature of B dopants in Si epitaxial layers grown on Si(001) substrates by the sputter epitaxy method. Specifically, we compared p-Si targets with two different surface orientations, (001) and (111). We found that the activation temperature depended on the crystallographic orientation of the B-doped p-Si target and B impurities began to be activated at a growth temperature of 680 °C when using the p-Si(111) target and at 560 °C, which is 120 °C lower, when using the p-Si(001) target. This phenomenon is discussed in this paper in terms of the difference in the level of crystallographic plane matching between the growth and target surfaces and the associated energetic barrier to B-atom activation. The case of P-doped Si (n-Si) was also compared, which showed no indication of target crystallographic orientation dependence, when comparing n-Si(001) and n-Si(111) targets, and the P activation began at around 250 °C. These findings are considered associated with P being more easily incorporated into Si lattice than B. The hole Hall scattering factors and estimated drift mobilities obtained with the p-Si(111) target were comparable to previously reported values, whereas those obtained with the p-Si(001) target were 0.17 and 15–23 % lower, respectively, suggesting that the p-Si layers grown using the p-Si(001) target had slightly more defects, possibly owing to lower growth temperatures.
{"title":"Reduced activation temperature of B impurities in Si(001) epitaxial layers grown by sputter epitaxy using B-doped Si(001) target compared with Si(111) target","authors":"Yoshiyuki Suda , Nobumitsu Hirose , Takahiro Tsukamoto , Akifumi Kasamatsu , Toshiaki Matsui","doi":"10.1016/j.jcrysgro.2025.128092","DOIUrl":"10.1016/j.jcrysgro.2025.128092","url":null,"abstract":"<div><div>We have investigated the effect of the crystallographic orientation of B-doped Si (p-Si) crystalline targets on the activation temperature of B dopants in Si epitaxial layers grown on Si(001) substrates by the sputter epitaxy method. Specifically, we compared p-Si targets with two different surface orientations, (001) and (111). We found that the activation temperature depended on the crystallographic orientation of the B-doped p-Si target and B impurities began to be activated at a growth temperature of 680 °C when using the p-Si(111) target and at 560 °C, which is 120 °C lower, when using the p-Si(001) target. This phenomenon is discussed in this paper in terms of the difference in the level of crystallographic plane matching between the growth and target surfaces and the associated energetic barrier to B-atom activation. The case of P-doped Si (n-Si) was also compared, which showed no indication of target crystallographic orientation dependence, when comparing n-Si(001) and n-Si(111) targets, and the P activation began at around 250 °C. These findings are considered associated with P being more easily incorporated into Si lattice than B. The hole Hall scattering factors and estimated drift mobilities obtained with the p-Si(111) target were comparable to previously reported values, whereas those obtained with the p-Si(001) target were 0.17 and 15–23 % lower, respectively, suggesting that the p-Si layers grown using the p-Si(001) target had slightly more defects, possibly owing to lower growth temperatures.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"654 ","pages":"Article 128092"},"PeriodicalIF":1.7,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143268977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.jcrysgro.2025.128090
Laszlo Sturz , Gerhard Zimmermann , Christoph Pickmann , Michael Ghosh , Youness Bami , Wim Sillekens , Ana Frutos Pastor , José Fernandez
We investigated dendritic solidification in the binary transparent organic model alloy neopentylglycol-(d)camphor under microgravity conditions onboard the International Space Station. Three cartridges containing alloys with hypoeutectic compositions of 0.2, 0.3 and 0.375 wt-frac. (d)Camphor were processed repeatedly in the “Transparent Alloys” solidification facility. In these Bridgman-type experiments, the dendritic grain structure − columnar, equiaxed or both mixed − was determined by in-situ optical observation as a function of alloy composition, crystallographic growth orientation, applied temperature field and cartridge withdrawal velocity. In most experiments, a columnar-equiaxed transition was achieved by increasing the cartridge velocity. We describe the experimental setup and procedure and focus on analysis of the columnar dendritic growth regime here. This includes estimates of the temperature gradient and supercooling at the columnar and eutectic front in combination with thermal modelling, as well as evaluation of a characteristic dendrite spacing. The results complement ground-based and other short-duration microgravity experiments in the same compositional range of the alloy. For eutectic growth, the undercooling increases linearly with cooling-rate. For columnar dendritic growth, the comparison of the kinetic law with previous experimental results exhibits similar trends but also significant deviations, which may be attributed to the different experimental set-up, data analysis and accuracy of temperature prediction. The determined characteristic dendrite spacing is well predicted by the models of Trivedi, Lu/Hunt and Ma/Sahm.
{"title":"Columnar dendritic growth during directional solidification of neopentylglycol-(d)camphor investigated under microgravity conditions","authors":"Laszlo Sturz , Gerhard Zimmermann , Christoph Pickmann , Michael Ghosh , Youness Bami , Wim Sillekens , Ana Frutos Pastor , José Fernandez","doi":"10.1016/j.jcrysgro.2025.128090","DOIUrl":"10.1016/j.jcrysgro.2025.128090","url":null,"abstract":"<div><div>We investigated dendritic solidification in the binary transparent organic model alloy neopentylglycol-(d)camphor under microgravity conditions onboard the International Space Station. Three cartridges containing alloys with hypoeutectic compositions of 0.2, 0.3 and 0.375 wt-frac. (d)Camphor were processed repeatedly in the “Transparent Alloys” solidification facility. In these Bridgman-type experiments, the dendritic grain structure − columnar, equiaxed or both mixed − was determined by <em>in-situ</em> optical observation as a function of alloy composition, crystallographic growth orientation, applied temperature field and cartridge withdrawal velocity. In most experiments, a columnar-equiaxed transition was achieved by increasing the cartridge velocity. We describe the experimental setup and procedure and focus on analysis of the columnar dendritic growth regime here. This includes estimates of the temperature gradient and supercooling at the columnar and eutectic front in combination with thermal modelling, as well as evaluation of a characteristic dendrite spacing. The results complement ground-based and other short-duration microgravity experiments in the same compositional range of the alloy. For eutectic growth, the undercooling increases linearly with cooling-rate. For columnar dendritic growth, the comparison of the kinetic law with previous experimental results exhibits similar trends but also significant deviations, which may be attributed to the different experimental set-up, data analysis and accuracy of temperature prediction. The determined characteristic dendrite spacing is well predicted by the models of Trivedi, Lu/Hunt and Ma/Sahm.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"655 ","pages":"Article 128090"},"PeriodicalIF":1.7,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-04DOI: 10.1016/j.jcrysgro.2025.128088
Marianna V. Kharlamova , Kiran Bal , Katarina Hutchin , Liam Jones , Reza J. Kasthiban , Jeremy Sloan
Metal chalcogenides have been interesting for researchers from the middle of the 20th century. In the 21st century, topological insulators based on metal chalcogenides are a developing and promising field. All such studies have mostly been dedicated to the atomic structure, optical, and electronic properties of these materials. In the present work, SWCNTs were filled with the the topological insulators bismuth selenide, and bismuth telluride. The microstructure of filled SWCNTs were investigated with high-resolution transmission electron microscopy (HRTEM) and annular dark field scanning transmission electron microscopy (ADF STEM). The electronic properties of the composite filled SWCNTs were studied with Raman spectroscopy, which show only a small modification to the electronic structure of nanotubes due to small band gap of the encapsulated chalcogenides. These results are promising for the applications of metal chalcogenide-filled SWCNTs in nanoelectronics, thermoelectric power generation devices, and biomedicine.
{"title":"One-dimensional bismuth chalcogenide-filled single-walled carbon nanotubes: Formation of solid solution and homologous nanostructures","authors":"Marianna V. Kharlamova , Kiran Bal , Katarina Hutchin , Liam Jones , Reza J. Kasthiban , Jeremy Sloan","doi":"10.1016/j.jcrysgro.2025.128088","DOIUrl":"10.1016/j.jcrysgro.2025.128088","url":null,"abstract":"<div><div>Metal chalcogenides have been interesting for researchers from the middle of the 20th century. In the 21st century, topological insulators based on metal chalcogenides are a developing and promising field. All such studies have mostly been dedicated to the atomic structure, optical, and electronic properties of these materials. In the present work, SWCNTs were filled with the the topological insulators bismuth selenide, and bismuth telluride. The microstructure of filled SWCNTs were investigated with high-resolution transmission electron microscopy (HRTEM) and annular dark field scanning transmission electron microscopy (ADF STEM). The electronic properties of the composite filled SWCNTs were studied with Raman spectroscopy, which show only a small modification to the electronic structure of nanotubes due to small band gap of the encapsulated chalcogenides. These results are promising for the applications of metal chalcogenide-filled SWCNTs in nanoelectronics, thermoelectric power generation devices, and biomedicine.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"654 ","pages":"Article 128088"},"PeriodicalIF":1.7,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143268976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The release of textile dyes into water systems poses a significant risk of increasing the prevalence of multidrug-resistant (MDR) organisms, which can have a detrimental effect on the health of both humans and animals. The efficacy of this method in the efficient removal of multidrug-resistant (MDR) organisms and deleterious dyes from effluent treatment for the purpose of environmental remediation is highly promising. The present study introduces novel zinc oxide nanoparticles (ZnONPs) that are made using Annona reticulata fruit extract as a reducing agent in a green production method. We employed UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy and field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDX) to analyse the ARF-ZnONPs that were generated through biosynthesis. The antibacterial effects of green synthesised ARF-ZnONPs were evaluated against both gram-positive and gram-negative bacteria. In addition, the degradation of azo dyes (methylene blue and reactive red 120) was measured under direct sunlight exposure. The ARF-ZnONPs were obtained with an absorption peak maximum at 369 nm, as evidenced by the UV–Vis spectrum. According to the research, the nucleation and stability of ARF-ZnONPs are influenced by phenolic compounds, alkaloids, terpenoids, and proteins present in the fruit extract of A. reticulata, as demonstrated by FT-IR analysis. A hexagonal wurtzite crystal structure is demonstrated in the XRD pattern of ARF-ZnONPs, with an average particle size of approximately 52 nm. The EDX spectrum verified the presence of the element Zn, and the FE-SEM image featured a hexagonal architecture. Against S. aureus, the maximum area of inhibition was 21.23 ± 0.35 mm, while against P. aeruginosa, it was 19.34 ± 0.26 mm. The degradation of azo dyes (MB and RR 120) was measured under direct sunlight exposure to evaluate the photocatalytic efficiency of ARF-ZnONPs. Thus, the aforementioned findings indicate that the ARF-ZnONPs synthesised using the environmentally benign method can be employed for a diverse array of antibacterial and environmental applications.
{"title":"Annona reticulata fruit-based phytosynthesis of zinc oxide nanoparticles and assess antioxidant, antibacterial and photocatalytic degradation of textile dyes","authors":"Thangam Chinnathambi , Kandasamy Selvam , Chinnappan Sudhakar , Arunagiri Ragu Prasath , Duraisamy Senbagam , Kanagarajan Saranya","doi":"10.1016/j.jcrysgro.2025.128087","DOIUrl":"10.1016/j.jcrysgro.2025.128087","url":null,"abstract":"<div><div>The release of textile dyes into water systems poses a significant risk of increasing the prevalence of multidrug-resistant (MDR) organisms, which can have a detrimental effect on the health of both humans and animals. The efficacy of this method in the efficient removal of multidrug-resistant (MDR) organisms and deleterious dyes from effluent treatment for the purpose of environmental remediation is highly promising. The present study introduces novel zinc oxide nanoparticles (ZnONPs) that are made using <em>Annona reticulata</em> fruit extract as a reducing agent in a green production method. We employed UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy and field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDX) to analyse the ARF-ZnONPs that were generated through biosynthesis. The antibacterial effects of green synthesised ARF-ZnONPs were evaluated against both gram-positive and gram-negative bacteria. In addition, the degradation of azo dyes (methylene blue and reactive red 120) was measured under direct sunlight exposure. The ARF-ZnONPs were obtained with an absorption peak maximum at 369 nm, as evidenced by the UV–Vis spectrum. According to the research, the nucleation and stability of ARF-ZnONPs are influenced by phenolic compounds, alkaloids, terpenoids, and proteins present in the fruit extract of <em>A. reticulata</em>, as demonstrated by FT-IR analysis. A hexagonal wurtzite crystal structure is demonstrated in the XRD pattern of ARF-ZnONPs, with an average particle size of approximately 52 nm. The EDX spectrum verified the presence of the element Zn, and the FE-SEM image featured a hexagonal architecture. Against <em>S. aureus</em>, the maximum area of inhibition was 21.23 ± 0.35 mm, while against <em>P. aeruginosa</em>, it was 19.34 ± 0.26 mm. The degradation of azo dyes (MB and RR 120) was measured under direct sunlight exposure to evaluate the photocatalytic efficiency of ARF-ZnONPs. Thus, the aforementioned findings indicate that the ARF-ZnONPs synthesised using the environmentally benign method can be employed for a diverse array of antibacterial and environmental applications.</div></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":"654 ","pages":"Article 128087"},"PeriodicalIF":1.7,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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