Pub Date : 2023-01-31DOI: 10.3389/fnano.2023.1057422
A. Zaman, Yuezhen Lu, N. Almond, Oliver J. Burton, J. Alexander-Webber, S. Hofmann, T. Mitchell, J. Griffiths, H. Beere, D. Ritchie, R. Degl’Innocenti
Active modification of the polarization state is a key feature for the next-generation of wireless communications, sensing, and imaging in the THz band. The polarization modulation performance of an integrated metamaterial/graphene device is investigated via a modified THz time domain spectroscopic system. Graphene’s Fermi level is modified through electrostatic gating, thus modifying the device’s overall optical response. Active tuning of ellipticity by > 0.3 is reported at the resonant frequency of 0.80 THz. The optical activity of transmitted THz radiations is continuously modified by > 21 . 5 o at 0.71 THz. By carefully selecting the transmitted frequency with the relative angle between the incoming linear polarization and the device’s symmetry axis, active circular dichroism and optical activity are almost independently exploited. Finally, this all-electronically tuneable versatile polarization device can be used in all applications requiring an ultrafast modulation such as polarization spectroscopy, imaging, and THz wireless generation.
{"title":"Versatile and active THz wave polarization modulators using metamaterial/graphene resonators","authors":"A. Zaman, Yuezhen Lu, N. Almond, Oliver J. Burton, J. Alexander-Webber, S. Hofmann, T. Mitchell, J. Griffiths, H. Beere, D. Ritchie, R. Degl’Innocenti","doi":"10.3389/fnano.2023.1057422","DOIUrl":"https://doi.org/10.3389/fnano.2023.1057422","url":null,"abstract":"Active modification of the polarization state is a key feature for the next-generation of wireless communications, sensing, and imaging in the THz band. The polarization modulation performance of an integrated metamaterial/graphene device is investigated via a modified THz time domain spectroscopic system. Graphene’s Fermi level is modified through electrostatic gating, thus modifying the device’s overall optical response. Active tuning of ellipticity by > 0.3 is reported at the resonant frequency of 0.80 THz. The optical activity of transmitted THz radiations is continuously modified by > 21 . 5 o at 0.71 THz. By carefully selecting the transmitted frequency with the relative angle between the incoming linear polarization and the device’s symmetry axis, active circular dichroism and optical activity are almost independently exploited. Finally, this all-electronically tuneable versatile polarization device can be used in all applications requiring an ultrafast modulation such as polarization spectroscopy, imaging, and THz wireless generation.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46680271","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 : 2023-01-24DOI: 10.3389/fnano.2023.1114267
P. Lomenzo, U. Celano, T. Kämpfe, S. Mcmitchell
Ferroelectric HfO2 and ZrO2-based materials are unconventional ferroelectrics compared to historically dominant perovskite-based ferroelectrics. These differences from conventional perovskite ferroelectrics are distinctly seen in HfO2-ZrO2’s fluorite-based structure that exhibits a rich polymorphism of competing crystal phases, enhanced ferroelectric behavior when scaling film thicknesses down to 10 nm and below, and a one order of magnitude lower relative permittivity and higher coercive field. Both the complex interplay of the fluorite crystal phases, as well as the intrinsic material and/or ferroelectric properties associated with them, have made ferroelectric HfO2-ZrO2-based ferroelectrics simultaneously challenging and interesting to characterize. Due in strong part to the nanoscale thicknesses of these fluorite-based ferroelectric films, the device behavior is an inseparable combination of the ferroelectric film properties (i.e., structure, crystalline orientation, grain size) and the material stack structure that encapsulates it into a two or three terminal device (i.e., interfaces, dielectric layers, electrode materials). Each article comprising this Research Topic on advanced characterization methods for HfO2/ZrO2-based ferroelectric illustrates different ways in which the intrinsic material properties or the ferroelectric film’s interaction with the device stack can be characterized to gain physical insight into this unconventional ferroelectric material system. Surface energy effects and grain size are often attributed to the predominant stabilization of either the non-polar tetragonal, monoclinic, or the polar orthorhombic phases in polycrystalline HfO2–ZrO2 films. It is generally observed that the polar orthorhombic phase is stabilized somewhere between the non-polar tetragonal and monoclinic phase boundaries, and that these non-polar phases are very sensitive to grain size in both HfO2 and ZrO2. Since the preferred crystal phase-dependence on grain size can be sensitive to stoichiometry (for instance, in Hf1xZrxO2 or Si-doped HfO2), it can be anticipated that there may be a complex interplay between grain-size engineering and ferroelectric film composition. In “Effect of Al2O3 interlayers on the microstructure and electrical response of ferroelectric doped HfO2 thin films” by Lederer et al., the grain-size and composition dependence of ferroelectric Hf1-xZrxO2 and Si-doped HfO2 is investigated in detail in which 1, 2, and 3 Al2O3 interlayers are used to control grain size while adjusting the stoichiometry of the fluorite-structured ferroelectric films. Using a combination of structural techniques, such as grazing-incidence X-ray diffraction and Kikuchi diffraction, as OPEN ACCESS
{"title":"Editorial: Advanced characterization methods for HfO2/ZrO2-based ferroelectrics","authors":"P. Lomenzo, U. Celano, T. Kämpfe, S. Mcmitchell","doi":"10.3389/fnano.2023.1114267","DOIUrl":"https://doi.org/10.3389/fnano.2023.1114267","url":null,"abstract":"Ferroelectric HfO2 and ZrO2-based materials are unconventional ferroelectrics compared to historically dominant perovskite-based ferroelectrics. These differences from conventional perovskite ferroelectrics are distinctly seen in HfO2-ZrO2’s fluorite-based structure that exhibits a rich polymorphism of competing crystal phases, enhanced ferroelectric behavior when scaling film thicknesses down to 10 nm and below, and a one order of magnitude lower relative permittivity and higher coercive field. Both the complex interplay of the fluorite crystal phases, as well as the intrinsic material and/or ferroelectric properties associated with them, have made ferroelectric HfO2-ZrO2-based ferroelectrics simultaneously challenging and interesting to characterize. Due in strong part to the nanoscale thicknesses of these fluorite-based ferroelectric films, the device behavior is an inseparable combination of the ferroelectric film properties (i.e., structure, crystalline orientation, grain size) and the material stack structure that encapsulates it into a two or three terminal device (i.e., interfaces, dielectric layers, electrode materials). Each article comprising this Research Topic on advanced characterization methods for HfO2/ZrO2-based ferroelectric illustrates different ways in which the intrinsic material properties or the ferroelectric film’s interaction with the device stack can be characterized to gain physical insight into this unconventional ferroelectric material system. Surface energy effects and grain size are often attributed to the predominant stabilization of either the non-polar tetragonal, monoclinic, or the polar orthorhombic phases in polycrystalline HfO2–ZrO2 films. It is generally observed that the polar orthorhombic phase is stabilized somewhere between the non-polar tetragonal and monoclinic phase boundaries, and that these non-polar phases are very sensitive to grain size in both HfO2 and ZrO2. Since the preferred crystal phase-dependence on grain size can be sensitive to stoichiometry (for instance, in Hf1xZrxO2 or Si-doped HfO2), it can be anticipated that there may be a complex interplay between grain-size engineering and ferroelectric film composition. In “Effect of Al2O3 interlayers on the microstructure and electrical response of ferroelectric doped HfO2 thin films” by Lederer et al., the grain-size and composition dependence of ferroelectric Hf1-xZrxO2 and Si-doped HfO2 is investigated in detail in which 1, 2, and 3 Al2O3 interlayers are used to control grain size while adjusting the stoichiometry of the fluorite-structured ferroelectric films. Using a combination of structural techniques, such as grazing-incidence X-ray diffraction and Kikuchi diffraction, as OPEN ACCESS","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42710064","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 : 2023-01-16DOI: 10.3389/fnano.2022.1096267
Eun Byoel Kim, Kyle Tomczak, H. B. Chandrasiri, Marcell Pálmai, A. Ghaznavi, D. Gritsenko, J. Xu, P. Snee
The use of microfluidics in chemical synthesis is topical due to the potential to improve reproducibility and the ability promptly interrogate a wide range of reaction parameters, the latter of which is necessary for the training of artificial intelligence (AI) algorithms. Applying microfluidic techniques to semiconductor nanocrystals, or quantum dots (QDs), is challenging due to the need for a high-temperature nucleation event followed by particle growth at lower temperatures. Such a high-temperature gradient can be realized using complex, segmented microfluidic reactor designs, which represents an engineering approach. Here, an alternative chemical approach is demonstrated using the cluster seed method of nanoparticle synthesis in a simple microfluidic reactor system. This enables quantum dot nucleation at lower temperatures due to the presence of molecular organometallic compounds (NMe4)4[Cd10Se4(SPh)16] and (NMe4)4[Zn10Se4(SPh)16]. This integration of cluster seeding with microfluidics affords a new mechanism to tailor the reaction conditions for optimizing yields and tuning product properties. Graphical Abstract
{"title":"Nucleation control of quantum dot synthesis in a microfluidic continuous flow reactor","authors":"Eun Byoel Kim, Kyle Tomczak, H. B. Chandrasiri, Marcell Pálmai, A. Ghaznavi, D. Gritsenko, J. Xu, P. Snee","doi":"10.3389/fnano.2022.1096267","DOIUrl":"https://doi.org/10.3389/fnano.2022.1096267","url":null,"abstract":"The use of microfluidics in chemical synthesis is topical due to the potential to improve reproducibility and the ability promptly interrogate a wide range of reaction parameters, the latter of which is necessary for the training of artificial intelligence (AI) algorithms. Applying microfluidic techniques to semiconductor nanocrystals, or quantum dots (QDs), is challenging due to the need for a high-temperature nucleation event followed by particle growth at lower temperatures. Such a high-temperature gradient can be realized using complex, segmented microfluidic reactor designs, which represents an engineering approach. Here, an alternative chemical approach is demonstrated using the cluster seed method of nanoparticle synthesis in a simple microfluidic reactor system. This enables quantum dot nucleation at lower temperatures due to the presence of molecular organometallic compounds (NMe4)4[Cd10Se4(SPh)16] and (NMe4)4[Zn10Se4(SPh)16]. This integration of cluster seeding with microfluidics affords a new mechanism to tailor the reaction conditions for optimizing yields and tuning product properties. Graphical Abstract","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48399014","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 : 2023-01-12DOI: 10.3389/fnano.2023.1087413
Prafull Shinde, A. Page, Sankha Bhattacharya
Skin cancer is one of the most prominent diseases, affecting all continents worldwide, and has shown a significant rise in mortality and prevalence. Conventional therapy, including chemotherapy and surgery, has a few drawbacks. The ethosomal systems would be thoroughly reviewed in this compilation, and they would be classified based on constituents: classical ethosomes, binary ethosomes, and transethosomes. Ethosomes systems are model lipid vesicular carriers with a substantial portion of ethanol. The impacts of ethosomal system components, preparation techniques, and their major roles in selecting the final characteristics of these nanocarriers are comprehensively reviewed in this chapter. The special techniques for ethosomes, including the cold approach, hot approach, injection method, mechanical dispersion method, and conventional method, are explained in this chapter. Various evaluation parameters of ethosomes were also explained. Furthermore, ethosomal gels, patches, and creams can be emphasised as innovative pharmaceutical drug formulations. Some hybrid ethosomal vesicles possessing combinatorial cancer therapy using nanomedicine could overcome the current drug resistance of specific cancer cells. Through the use of repurpose therapy, phytoconstituents may be delivered more effectively. A wide range of in vivo models are employed to assess their effectiveness. Ethosomes have provided numerous potential skin cancer therapeutic approaches in the future.
{"title":"Ethosomes and their monotonous effects on Skin cancer disruption","authors":"Prafull Shinde, A. Page, Sankha Bhattacharya","doi":"10.3389/fnano.2023.1087413","DOIUrl":"https://doi.org/10.3389/fnano.2023.1087413","url":null,"abstract":"Skin cancer is one of the most prominent diseases, affecting all continents worldwide, and has shown a significant rise in mortality and prevalence. Conventional therapy, including chemotherapy and surgery, has a few drawbacks. The ethosomal systems would be thoroughly reviewed in this compilation, and they would be classified based on constituents: classical ethosomes, binary ethosomes, and transethosomes. Ethosomes systems are model lipid vesicular carriers with a substantial portion of ethanol. The impacts of ethosomal system components, preparation techniques, and their major roles in selecting the final characteristics of these nanocarriers are comprehensively reviewed in this chapter. The special techniques for ethosomes, including the cold approach, hot approach, injection method, mechanical dispersion method, and conventional method, are explained in this chapter. Various evaluation parameters of ethosomes were also explained. Furthermore, ethosomal gels, patches, and creams can be emphasised as innovative pharmaceutical drug formulations. Some hybrid ethosomal vesicles possessing combinatorial cancer therapy using nanomedicine could overcome the current drug resistance of specific cancer cells. Through the use of repurpose therapy, phytoconstituents may be delivered more effectively. A wide range of in vivo models are employed to assess their effectiveness. Ethosomes have provided numerous potential skin cancer therapeutic approaches in the future.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41599358","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 : 2023-01-12DOI: 10.3389/fnano.2022.1058973
I. Athal, I. Sarris, Palani Velusamy, V. Govindan
The method of regular perturbation is used to analyse the fully developed flow and heat transfer in a vertical two-way channel containing a permeable liquid. The Brinkman model is used for flow through porous media. The energy equation contains a viscosity term and a Darcy dissipation term. The fully conductive thin partition is divided into two stages; the wall is uniformly heated; and the effects of the porous parameter σ and the mixed convection parameter λ on the velocity and temperature distribution near the hot and cold walls are investigated. The results show that these effects mainly depend on the position of the baffle. Analytical solutions are first used to resolve the simpler problems of either a negligible Brinkman number or a negligible Grashof number. Then, using a perturbation series method, the combined effects of buoyant forces and viscous dissipation are examined. The velocity field and the temperature field in the cases under study were assessed.
{"title":"Viscosity dissipation and mixed convection flow in a vertical double-passage channel with permeable fluid","authors":"I. Athal, I. Sarris, Palani Velusamy, V. Govindan","doi":"10.3389/fnano.2022.1058973","DOIUrl":"https://doi.org/10.3389/fnano.2022.1058973","url":null,"abstract":"The method of regular perturbation is used to analyse the fully developed flow and heat transfer in a vertical two-way channel containing a permeable liquid. The Brinkman model is used for flow through porous media. The energy equation contains a viscosity term and a Darcy dissipation term. The fully conductive thin partition is divided into two stages; the wall is uniformly heated; and the effects of the porous parameter σ and the mixed convection parameter λ on the velocity and temperature distribution near the hot and cold walls are investigated. The results show that these effects mainly depend on the position of the baffle. Analytical solutions are first used to resolve the simpler problems of either a negligible Brinkman number or a negligible Grashof number. Then, using a perturbation series method, the combined effects of buoyant forces and viscous dissipation are examined. The velocity field and the temperature field in the cases under study were assessed.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42369736","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}
With the popularity of nanotechnology, the use of nanoparticles in pest management has become widespread. Nanoformulated pesticides have several advantages over conventional pesticide formulations, including improved environmental stability, controlled release of active ingredients, increased permeability, targeted delivery, etc. Despite these advantages, recent research shows that several nanoparticles used in conventional nanopesticide formulations can be toxic to crops and beneficial organisms due to bioaccumulation and trophic transfer. Therefore, traditional nanopesticides are thought to be non-advantageous for “green agriculture”. In assessing the current situation, developing “all-organic” nanopesticides could be the next-generation weapon for reducing the adverse impact of traditional nanopesticides. However, their formulation and application knowledge is remarkably limited. The green synthesis of “all-organic” nanoparticles makes them more environmentally friendly than conventional nanopesticides due to their minimal residual and hazardous effects. This review focuses on the current development scenario of “all-organic” nanopesticides, their advantages, and potential effects on target organisms compared to traditional nanopesticides. Graphical Abstract
{"title":"Current and future prospects of “all-organic” nanoinsecticides for agricultural insect pest management","authors":"Sourav Manna, Sampurna Roy, Avishek Dolai, Arunreddy Ravula, Venkatesan Perumal, Amlan Das","doi":"10.3389/fnano.2022.1082128","DOIUrl":"https://doi.org/10.3389/fnano.2022.1082128","url":null,"abstract":"With the popularity of nanotechnology, the use of nanoparticles in pest management has become widespread. Nanoformulated pesticides have several advantages over conventional pesticide formulations, including improved environmental stability, controlled release of active ingredients, increased permeability, targeted delivery, etc. Despite these advantages, recent research shows that several nanoparticles used in conventional nanopesticide formulations can be toxic to crops and beneficial organisms due to bioaccumulation and trophic transfer. Therefore, traditional nanopesticides are thought to be non-advantageous for “green agriculture”. In assessing the current situation, developing “all-organic” nanopesticides could be the next-generation weapon for reducing the adverse impact of traditional nanopesticides. However, their formulation and application knowledge is remarkably limited. The green synthesis of “all-organic” nanoparticles makes them more environmentally friendly than conventional nanopesticides due to their minimal residual and hazardous effects. This review focuses on the current development scenario of “all-organic” nanopesticides, their advantages, and potential effects on target organisms compared to traditional nanopesticides. Graphical Abstract","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47165511","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 : 2023-01-06DOI: 10.3389/fnano.2022.1084033
C. K. Singh, K. K. Sodhi
COVID-19, one of the worst-hit pandemics, has quickly spread like fire across nations with very high mortality rates. Researchers all around the globe are making consistent efforts to address the main challenges faced due to COVID-19 infection including prompt diagnosis and therapeutics to reduce mortality. Conventional medical technology does not effectively contain the havoc caused by deadly COVID-19. This signals a crucial mandate for innovative and novel interventions in diagnostics and therapeutics to combat this ongoing pandemic and counter its successor or disease if it were ever to arise. The expeditious solutions can spring from promising areas such as nanomedicine and nanotechnology. Nanomedicine is a dominant tool that has a huge potential to alleviate the disease burden by providing nanoparticle-based vaccines and carriers. Nanotechnology encompasses multidisciplinary aspects including artificial intelligence, chemistry, biology, material science, physical science, and medicine. Nanoparticles offer many advantages compared to larger particles, including better magnetic properties and a multiplied surface-to-volume ratio. Given this, the present review focuses on promising nanomedicine-based solutions to combat COVID-19 and their utility to control a broad range of pathogens and viruses, along with understanding their role in the therapy, diagnosis, and prevention of COVID-19. Various studies, reports, and recent research and development from the nanotechnology perspective are discussed in this article.
{"title":"The emerging significance of nanomedicine-based approaches to fighting COVID-19 variants of concern: A perspective on the nanotechnology’s role in COVID-19 diagnosis and treatment","authors":"C. K. Singh, K. K. Sodhi","doi":"10.3389/fnano.2022.1084033","DOIUrl":"https://doi.org/10.3389/fnano.2022.1084033","url":null,"abstract":"COVID-19, one of the worst-hit pandemics, has quickly spread like fire across nations with very high mortality rates. Researchers all around the globe are making consistent efforts to address the main challenges faced due to COVID-19 infection including prompt diagnosis and therapeutics to reduce mortality. Conventional medical technology does not effectively contain the havoc caused by deadly COVID-19. This signals a crucial mandate for innovative and novel interventions in diagnostics and therapeutics to combat this ongoing pandemic and counter its successor or disease if it were ever to arise. The expeditious solutions can spring from promising areas such as nanomedicine and nanotechnology. Nanomedicine is a dominant tool that has a huge potential to alleviate the disease burden by providing nanoparticle-based vaccines and carriers. Nanotechnology encompasses multidisciplinary aspects including artificial intelligence, chemistry, biology, material science, physical science, and medicine. Nanoparticles offer many advantages compared to larger particles, including better magnetic properties and a multiplied surface-to-volume ratio. Given this, the present review focuses on promising nanomedicine-based solutions to combat COVID-19 and their utility to control a broad range of pathogens and viruses, along with understanding their role in the therapy, diagnosis, and prevention of COVID-19. Various studies, reports, and recent research and development from the nanotechnology perspective are discussed in this article.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46328606","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 : 2023-01-03DOI: 10.3389/fnano.2023.1134850
R. M. Abraham-Ekeroth
Introduction: The formation of a stable magneto plasmonic dimer with THz resonances is theoretically studied for the principal directions of the system. Unlike a recent report, our work provides a complete description of the full photonic coupling for arbitrary magnetic fields as, for instance, unbalanced particle spins. Methods: As an illustration, we consider two small, n-doped InSb nanoparticles under illumination by two counter-propagating plane waves. Results: Remarkably, when an external magnetic field exists, the symmetry in the system is broken, and a resonant radiation pressure for the dimer appears. Similarly, tunable inter-particle forces and spins are exerted on the non-reciprocal dimer. The system is also characterized when the magnetic field is absent. Moreover, we show how the mechanical observables truly characterize the dimer since their resonance dependency contains detailed information about the system. Discussion: Unlike far-field observables like absorption, mechanical magnitudes depend on the system's near-field. In addition, the nature of the particle spins is originally explained by the energy flow's behavior around the dimer. This work constitutes a generalization of any previous approach to optical binding between small nanoparticles. It paves the way for fully controlling optical matter and nano factory designs based on surface plasmon polaritons.
{"title":"Numerical study of magneto-optical binding between two dipolar particles under illumination by two counter-propagating waves","authors":"R. M. Abraham-Ekeroth","doi":"10.3389/fnano.2023.1134850","DOIUrl":"https://doi.org/10.3389/fnano.2023.1134850","url":null,"abstract":"Introduction: The formation of a stable magneto plasmonic dimer with THz resonances is theoretically studied for the principal directions of the system. Unlike a recent report, our work provides a complete description of the full photonic coupling for arbitrary magnetic fields as, for instance, unbalanced particle spins. Methods: As an illustration, we consider two small, n-doped InSb nanoparticles under illumination by two counter-propagating plane waves. Results: Remarkably, when an external magnetic field exists, the symmetry in the system is broken, and a resonant radiation pressure for the dimer appears. Similarly, tunable inter-particle forces and spins are exerted on the non-reciprocal dimer. The system is also characterized when the magnetic field is absent. Moreover, we show how the mechanical observables truly characterize the dimer since their resonance dependency contains detailed information about the system. Discussion: Unlike far-field observables like absorption, mechanical magnitudes depend on the system's near-field. In addition, the nature of the particle spins is originally explained by the energy flow's behavior around the dimer. This work constitutes a generalization of any previous approach to optical binding between small nanoparticles. It paves the way for fully controlling optical matter and nano factory designs based on surface plasmon polaritons.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44626158","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 : 2022-12-16DOI: 10.3389/fnano.2022.1092177
Miguel Rengifo, M.H. Aguirre, M. Sirena, U. Lüders, D. Rubi
Neuromorphic computing requires the development of solid-state units able to electrically mimic the behavior of biological neurons and synapses. This can be achieved by developing memristive systems based on ferroelectric oxides. In this work we fabricate and characterize high quality epitaxial BaTiO3-based memristors integrated with silicon. After proving the ferroelectric character of BaTiO3 we tested the memristive response of LaNiO3/BaTiO3/Pt microstructures and found a complex behavior which includes the co-existence of volatile and non-volatile effects, arising from the modulation of the BaTiO3/Pt Schottky interface by the direction of the polarization coupled to oxygen vacancy electromigration to/from the interface. This produces remanent resistance loops with tunable ON/OFF ratio and asymmetric resistance relaxations. These properties might be harnessed for the development of neuromorphic hardware compatible with existing silicon-based technology.
{"title":"Epitaxial ferroelectric memristors integrated with silicon","authors":"Miguel Rengifo, M.H. Aguirre, M. Sirena, U. Lüders, D. Rubi","doi":"10.3389/fnano.2022.1092177","DOIUrl":"https://doi.org/10.3389/fnano.2022.1092177","url":null,"abstract":"Neuromorphic computing requires the development of solid-state units able to electrically mimic the behavior of biological neurons and synapses. This can be achieved by developing memristive systems based on ferroelectric oxides. In this work we fabricate and characterize high quality epitaxial BaTiO3-based memristors integrated with silicon. After proving the ferroelectric character of BaTiO3 we tested the memristive response of LaNiO3/BaTiO3/Pt microstructures and found a complex behavior which includes the co-existence of volatile and non-volatile effects, arising from the modulation of the BaTiO3/Pt Schottky interface by the direction of the polarization coupled to oxygen vacancy electromigration to/from the interface. This produces remanent resistance loops with tunable ON/OFF ratio and asymmetric resistance relaxations. These properties might be harnessed for the development of neuromorphic hardware compatible with existing silicon-based technology.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43704706","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 : 2022-12-13DOI: 10.3389/fnano.2022.1064615
F. Hussain, Naveed Qasim Abro, N. Ahmed, S. Memon, Najma Memon
Nanoparticles can be used as inhibitory agents against various microorganisms, including bacteria, algae, archaea, fungi, and a huge class of viruses. The mechanism of action includes inhibiting the function of the cell membrane/stopping the synthesis of the cell membrane, disturbing the transduction of energy, producing toxic reactive oxygen species (ROS), and inhibiting or reducing RNA and DNA production. Various nanomaterials, including different metallic, silicon, and carbon-based nanomaterials and nanoarchitectures, have been successfully used against different viruses. Recent research strongly agrees that these nanoarchitecture-based virucidal materials (nano-antivirals) have shown activity in the solid state. Therefore, they are very useful in the development of several products, such as fabric and high-touch surfaces. This review thoroughly and critically identifies recently developed nano-antivirals and their products, nano-antiviral deposition methods on various substrates, and possible mechanisms of action. By considering the commercial viability of nano-antivirals, recommendations are made to develop scalable and sustainable nano-antiviral products with contact-killing properties. Graphical Abstract
{"title":"Nano-antivirals: A comprehensive review","authors":"F. Hussain, Naveed Qasim Abro, N. Ahmed, S. Memon, Najma Memon","doi":"10.3389/fnano.2022.1064615","DOIUrl":"https://doi.org/10.3389/fnano.2022.1064615","url":null,"abstract":"Nanoparticles can be used as inhibitory agents against various microorganisms, including bacteria, algae, archaea, fungi, and a huge class of viruses. The mechanism of action includes inhibiting the function of the cell membrane/stopping the synthesis of the cell membrane, disturbing the transduction of energy, producing toxic reactive oxygen species (ROS), and inhibiting or reducing RNA and DNA production. Various nanomaterials, including different metallic, silicon, and carbon-based nanomaterials and nanoarchitectures, have been successfully used against different viruses. Recent research strongly agrees that these nanoarchitecture-based virucidal materials (nano-antivirals) have shown activity in the solid state. Therefore, they are very useful in the development of several products, such as fabric and high-touch surfaces. This review thoroughly and critically identifies recently developed nano-antivirals and their products, nano-antiviral deposition methods on various substrates, and possible mechanisms of action. By considering the commercial viability of nano-antivirals, recommendations are made to develop scalable and sustainable nano-antiviral products with contact-killing properties. Graphical Abstract","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44268584","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}
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