Nano Express最新文献

{"title":"Three-dimensional SnO2 nanoparticles synthesized by joule heating as anode materials for lithium ion batteries","authors":"Woo-Bin Jung, Yu Hong, Jeesoo Yoon, S. Moon, Sungho Choi, Do Youb Kim, Jungdon Suk, Oh B. Chae, Mihye Wu, Hee‐Tae Jung","doi":"10.1088/2632-959X/ac6e78","DOIUrl":"https://doi.org/10.1088/2632-959X/ac6e78","url":null,"abstract":"Tin dioxide (SnO2) is a promising material for use as anodes because of its high theoretical capacity (1,494 mAh g−1). However, a critical limitation is the large change in volume during repeated cycling by pulverization of SnO2, which results in capacity fading. In this study, we enhanced cycle life and reduced capacity fading by introducing the use of three-dimensional SnO2 nanoparticles on carbon nanofibers (CNFs) as an anode material, which is fabricated by simple carbothermal shock through the Joule heating method. Our observations show that the SnO2 nanoparticles are about 50 nm in diameter and are uniformly distributed on CNF, and that the strong connections between SnO2 nanoparticles and CNF are sustained even after repeated cycling. This structural advantage provides high reversible capacity and enhanced cycle performance for over 100 cycles. This study provides insight into the fabrication of anode materials that have strong electric connections between active materials and conductive materials due to the Joule heating method for high-performance lithium ion batteries.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129871433","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}

{"title":"Scaling of voltage controlled magnetic anisotropy based skyrmion memory and its neuromorphic application","authors":"Md. Rakibul Karim Akanda","doi":"10.1088/2632-959X/ac6bb5","DOIUrl":"https://doi.org/10.1088/2632-959X/ac6bb5","url":null,"abstract":"Voltage controlled skyrmion memory requires less energy compared to current controlled method where voltage changes magnetic anisotropy (VCMA) and Dzyaloshinskii-Moriya interaction (DMI). Ferromagnetic (FM) and synthetic antiferromagnetic (SAFM) memory devices are simulated using electric field control method where gate and gap width are chosen as smaller than skyrmion size so that skyrmion can feel the change in voltage polarity in the neighbouring gate and moves accordingly. Scaling of memory device is performed which shows SAFM memory can be made much narrower compared to FM memory as skyrmion diameter also depends on width of the structure. Effects of device structure and skyrmion-skyrmion repulsion force on skyrmion diameter variation are shown in cylindrical structure considering effect of demagnetizing field. Apart from these, neuromorphic application is considered where skyrmion moves from central square neuron region to surrounding synapse region or vice versa by the application of voltage. Switching time, voltage range, energy and scaling of device dimensions are shown for synapse-neuron having different number of skyrmions where multiple skyrmions represent different weight in the neuromorphic circuit.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133120844","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}

{"title":"Silver nanoprism-mediated protein estimation—an ultrasensitive platform for rapid estimation of protein concentration","authors":"Katha Shyam Sundar, Jatavath Ramesh, P. Chinthala, Karunakar Rao, Swagata Banerjee, Shibsekhar Roy","doi":"10.1088/2632-959X/ac6968","DOIUrl":"https://doi.org/10.1088/2632-959X/ac6968","url":null,"abstract":"Estimation of protein concentration in the range of nanogram level (ng/ml) is a big challenge for conventional protein estimation methods. The highly dipole sensitive spectroscopic properties of Silver nanoprism (AgNPR) has been utilized to develop a rapid and highly sensitive method for the estimation of globular protein concentration at ng/ml (or ppb) range. We have applied a unique molecular doping approach to introduce protein in the interstitial space of the Ag fcc(111) crystal planes within AgNPR structure. The presence of the doped protein induces deformation in the crystal plane arrangement of AgNPR that results in a quantitative red shift of the dipole resonance peak (D-peak) of AgNPR under UV–vis spectroscopy. The proposed method allows detection of a protein concentration range of as low as 1–20 ng ml−1- that is better than the sensitivity limit of conventional protein estimation techniques. This method has been successfully applied for commonly used proteins like haemoglobin (Hb), Bovine serum albumin (BSA), Trypsin (TRYP) and Lysozyme (LYS) with a very low limit of detection (LOD) within 2–6 ng ml−1. The lowest LOD value was shown by Hb as 2.08 ng ml−1. The method has further been validated by measuring Casein concentration from milk with an accuracy of 99% and 95% recovery for the concentration of 3.1 and 31 ng ml−1 respectively. Transmission emission microscopy (TEM) images show that the doped protein has been found to alter the size and shape of the AgNPR as a function of the dopant concentration by creating systematic deformation. This method does not require any alteration of the reaction temperature and solely depends on the physical interaction of doped protein with its neighbouring crystal structure of the nanoplanar geometry.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127623603","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}

{"title":"Bottom-up synthesis of meta-atoms as building blocks in self-assembled metamaterials: recent advances and perspectives","authors":"L. Lermusiaux, Lucien Roach, A. Baron, M. Tréguer-Delapierre","doi":"10.1088/2632-959X/ac6889","DOIUrl":"https://doi.org/10.1088/2632-959X/ac6889","url":null,"abstract":"Meta-atoms interact with light in interesting ways and offer a large range of exciting properties. They exhibit optical properties inaccessible by natural atoms but their fabrication is notoriously difficult because of the precision required. In this perspective, we present the current research landscape in making meta-atoms, with a focus on the most promising self-assembly approaches and main challenges to overcome, for the development of materials with novel properties at optical frequencies.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123612613","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}

{"title":"Humidity response of a capacitive sensor based on auxeticity of carbon nanotube-paper composites","authors":"Zhongjie Qian, Tianyi Li, Vigneshwar Sakthivelpathi, Sheila M. Goodman, Anthony B. Dichiara, A. Mamishev, J. Chung","doi":"10.1088/2632-959X/ac6764","DOIUrl":"https://doi.org/10.1088/2632-959X/ac6764","url":null,"abstract":"Auxetic materials showing a negative Poisson’s ratio can offer unusual sensing capabilities due to drastic percolation changes. This study presents the capacitive response of wet-fractured carbon nanotube paper composites in exposure to humidity. A strained composite strip is fractured to produce numerous cantilevers consisting of cellulose fibers coated with carbon nanotubes. During stretching, the thin composite buckles in the out-of-plane direction, which causes auxetic behavior to generate the radially structured electrodes. The crossbar junctions forming among the fractured electrodes significantly increase capacitance and its response to humidity as a function of sensor widths. The molecular junctions switch electric characteristics between predominantly resistive- and capacitive elements. The resulting capacitive response is characterized for humidity sensing without the need for an additional absorption medium. The normalized capacitance change (ΔC/C0) exhibits a sensitivity of 0.225 within the range of 40 ∼ 80% relative humidity. The novel auxetic behavior of a water-printed paper-based nanocomposite paves the way for inexpensive humidity and sweat sensors.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125202933","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}

{"title":"Particle swarm optimization of GaAs-AlGaAS nanowire photonic crystals as two-dimensional diffraction gratings for light trapping","authors":"L. Zagaglia, V. Demontis, F. Rossella, F. Floris","doi":"10.1088/2632-959X/ac61ec","DOIUrl":"https://doi.org/10.1088/2632-959X/ac61ec","url":null,"abstract":"Semiconductor nanowire ordered arrays represent a class of bi-dimensional photonic crystals that can be engineered to obtain functional metamaterials. Here is proposed a novel approach, based on a particle swarm optimization algorithm, for using such a photonic crystal concept to design a semiconductor nanowire-based two-dimensional diffraction grating able to guarantee an in-plane coupling for light trapping. The method takes into account the experimental constraints associated to the bottom-up growth of nanowire arrays, by processing as input dataset all relevant geometrical and morphological features of the array, and returns as output the optimised set of parameters according to the desired electromagnetic functionality of the metamaterial. A case of study based on an array of tapered GaAs-AlGaAs core–shell nanowire heterostructures is discussed.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"55 32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128364282","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}

{"title":"Field-effect surface chemistry: chemical reactions on two-dimensional materials controlled by field-effect transistor configurations","authors":"R. Nouchi","doi":"10.1088/2632-959X/ac603f","DOIUrl":"https://doi.org/10.1088/2632-959X/ac603f","url":null,"abstract":"Because chemical reactions are largely governed by the movement of electrons, it is possible to control chemical reactions using electronic devices that provide functionality by controlling the movement of electrons in a solid. In this perspective, we discuss the concept of ‘field-effect surface chemistry,’ which controls chemical reactions on two-dimensional materials using field-effect transistors (FETs), a representative electronic device. The electrical voltages to be applied for the FET operation are the gate voltage and drain voltage. The former is expected to control the Fermi level and exert the effect of the electric field directly on the reactants, while the latter is expected to provide local heating by Joule heat and energy transfer to the reactants. Further, we discuss a sample structure that does not require any voltage but has the same effect as the gate voltage.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132602320","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}

{"title":"Printed electronics to accelerate solid-state battery development","authors":"R. Sliz, Palanivel Molaiyan, T. Fabritius, U. Lassi","doi":"10.1088/2632-959X/ac5d8e","DOIUrl":"https://doi.org/10.1088/2632-959X/ac5d8e","url":null,"abstract":"The transition from conventional liquid electrolyte Li-ion batteries towards solid-state systems requires a paradigm shift on how these batteries are fabricated and how the R&D process can be augmented in order to fulfil the ever-increasing demand for reliable and high-performance energy storage systems. This work briefly looks over the main aspects of printed electronics and its potential to accelerate the development of solid-state batteries. It emphasizes the main challenges related to the fabrication of solid-state batteries and how printed electronics can address them in a timely and affordable manner. Importantly, the proposed printed electronics methods and solutions highlight the ability for immediate upscaling to mass production as well as downscaling for rapid prototyping and custom designing.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130408446","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}

{"title":"Two-step deposition of TiN capping electrodes to prevent degradation of ferroelectric properties in an in-situ crystallized TiN/Hf0.5Zr0.5O2/TiN device","authors":"Hyungwoo Kim, Alireza Kashir, Hojung Jang, Seungyeol Oh, M. Yadav, Seungwoo Lee, Hyun-Hee Hwang","doi":"10.1088/2632-959X/ac5be5","DOIUrl":"https://doi.org/10.1088/2632-959X/ac5be5","url":null,"abstract":"Hf0.5Zr0.5O2 (HZO) is an appropriate material for the back-end-of-line (BEOL) process in fabricating ferroelectric TiN/HZO/TiN devices because of its excellent conformality on 3D nanostructures and a suitable crystallization temperature (≥ 350 °C–400 °C). However, in the semiconductor industry, the deposition temperature of TiN is usually higher than 400 °C. Therefore, it is necessary to study the ferroelectric properties of TiN/HZO/TiN devices when the deposition temperature of the TiN top electrode is higher than the HZO film crystallization temperature. In this study, 10-nm-thick TiN top electrodes were deposited at various temperatures on the HZO thin film to investigate the impact of the TiN deposition temperature on the structural features and ferroelectric properties of TiN/HZO/TiN capacitors. Only the sample capped with a TiN top electrode deposited at 400 °C showed ferroelectric properties without subsequent annealing (in situ crystallization). However, this sample exhibited an approximately 40% reduction in the polarization value compared with the other samples that were crystallized after the annealing process. This behavior can be ascribed to the formation of a monoclinic nonpolar phase. To prevent the degradation of the polarization value and suppress the formation of the m-phase in the in situ crystallized HZO thin film, a two-step TiN deposition method was carried out. The sample was fabricated by depositing a 5-nm-thick TiN top electrode at room temperature followed by the deposition of a 5-nm-thick TiN layer at 400 °C, which resulted in strong ferroelectric properties comparable to those of the samples capped with TiN grown at relatively low temperatures (room temperature, 200 °C, and 300 °C). These findings can adequately explain the role of the capping layer in achieving the ferroelectric phase, which is closely related not only during the cooling step of any thermal process but also during the heating and crystallization steps.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131650744","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}

{"title":"Montmorillonite-based heterogeneous catalysts for efficient organic reactions","authors":"Moe Takabatake, Ken Motokura","doi":"10.1088/2632-959X/ac5ac3","DOIUrl":"https://doi.org/10.1088/2632-959X/ac5ac3","url":null,"abstract":"In this review, we give a brief overview of recently developed montmorillonite-based heterogeneous catalysts used for efficient organic reactions. Cation-exchanged montmorillonite catalysts, metal catalysts supported on montmorillonite, and an interlayer design used for selective catalysis are introduced and discussed. In traditional syntheses, homogeneous acids and metal salts were used as catalysts, but the difficulty in separation of catalysts from products was a bottleneck when considering industrialization. The use of solid heterogeneous catalysts is one of the major solutions to overcome this problem. Montmorillonite can be used as a heterogeneous catalyst and/or catalyst support. This clay material exhibits strong acidity and a stabilizing effect on active species, such as metal nanoparticles, due to its unique layered structure. These advantages have led to the development of montmorillonite-based heterogeneous catalysts. Acidic montmorillonite, such as proton-exchanged montmorillonite, exhibits a high catalytic activity for the activation of electrophiles, such as alcohols, alkenes, and even alkanes. The montmorillonite interlayer/surface also functions as a good support for various metal species used for oxidation and carbon-carbon bond forming reactions. The use of an interlayer structure enables selective reactions and the stabilization of catalytically active species.","PeriodicalId":118165,"journal":{"name":"Nano Express","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114155181","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}