Online ISSN
1750-0443
Micro & Nano Letters
Volume 7, Issue 4, April 2012
Volumes & issues:
Volume 7, Issue 4
April 2012
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- Author(s): L. Curri ; G. Fedder ; B.L. Pruitt
- Source: Micro & Nano Letters, Volume 7, Issue 4, page: 296 –296
- DOI: 10.1049/mnl.2012.0244
- Type: Article
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- Author(s): N. Sarkar ; K. Trainor ; R.R. Mansour
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 297 –300
- DOI: 10.1049/mnl.2011.0470
- Type: Article
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The authors report on the operation of complementary metal-oxide semiconductor microelectromechanical system (MEMS) scanning probe microscope (SPM) with integrated three-dimensional electrothermal actuation and three-axis position sensing. Conventional SPM makes use of piezoelectric positioning systems which are bulky (leading to thermal drift and poor vibration immunity) and suffer from inherent creep (leading to image distortion). The scanner design is intended to leverage the myriad physical benefits of dimensional scaling to improve the performance and to reduce the barrier to entry for SPM ownership when compared to the state-of-the-art. However, the integration of multiple electrothermal actuators on chip introduces several complications owing to coupling between electrical, thermal and mechanical domains. The focus of this Letter is to discuss the origins of these effects, and the strategies that are implemented to mitigate them. Specifically, the authors discuss the open-loop and closed-loop control methods that are used to drive the lateral and vertical actuators and propose and verify a method to compensate for the parasitic effects observed in the piezoresistive force sensors. To the best of the authors' knowledge, this is the first integrated MEMS-SPM with multiple imaging modes that can image a sample without the need for off-chip scanners or laser-based position sensing. - Author(s): F. Loizeau ; T. Akiyama ; S. Gautsch ; A. Meister ; P. Vettiger ; N.F. de Rooij
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 301 –305
- DOI: 10.1049/mnl.2011.0467
- Type: Article
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A fabrication process for realising two-dimensional cantilever arrays for parallel force spectroscopy of biological samples is presented. The parallel optical atomic force microscopy readout system has been developed and presented elsewhere. The arrays are designed either for (i) force-indentation onto living cells to obtain stiffness mapping or (ii) cell adhesion experiments. Both experiments require very different spring constants and tip radii of curvature. The arrays are based on silicon nitride cantilevers with molded tips. The fabrication process includes an advanced molding process and a thermocompression bonding of two silicon wafers. V-groove structures along the cantilevers, which increase the area moment of inertia, were introduced in the cantilever design. This feature enables the fabrication of cantilevers with different spring constants but same footprint from one wafer. An analytical model and experimental results confirmed that the spring constant of the cantilever (200×50×0.45 µm) could be increased up to two decades (0.03–5 N/m) by changing the depth of the V-grooves. To realise the large tip radius required for cell adhesion experiments, an enlarging/rounding procedure has been applied to a truncated pyramidal tip mold. With this process, the authors obtained tips with a radius up to 4 µm. - Author(s): Cui Yan ; Zhao Lin ; Dong Weijie ; Wang Fei ; Wang Liding
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 306 –308
- DOI: 10.1049/mnl.2011.0374
- Type: Article
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This Letter focuses on the piezoelectric microcantilever probe fabrication processes. The sensing layer was lead zirconate titanate (PZT) thin films, prepared by sol–gel process, and formed on the Pt/Ti/SiO2/Si (100) substrate. The silicon-based microcantilever probe fabrication process is based on the microelectromechanical system technology. The compatible processes make the PZT thin films successfully fabricated on the silicon-based microcantilever. The size of piezoelectric cantilever is 450 µm in length, 70 µm in width and 12 µm in thickness. The spring constant of the cantilever probe is 41.28 N/m measured by the micro-force testing system. The first resonance frequency of the cantilever probe is 43.78 KHz. The low leakage current of the PZT thin films is 0.265 nA with the applied voltage of 1 V. The results reveal that the piezoelectric cantilever probe can be substituted for the traditional atomic force microscopy probe. - Author(s): S.P. Wadikhaye ; Y.K. Yong ; S.O.R. Moheimani
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 309 –313
- DOI: 10.1049/mnl.2011.0477
- Type: Article
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A systematic procedure for designing a high-speed, compact serial-kinematic XYZ scanner for atomic force microscopy is presented in this Letter. Analytical stiffness calculations are used to estimate the first natural frequency and travel range of the scanner. Design and characterisation of the scanner are presented. Results of finite-element analysis and experimentation on the scanner revealed natural frequencies of 10, 7.5 and 64 kHz for X, Y and Z stages, respectively. Maximum travel range of 8, 6 and 2 µm were measured along x, y and z directions. Performance evaluations were conducted by implementing the scanner in a commercial atomic force microscope. Images of a 6×4.5 µm area of a calibration grating were captured at line rates of 10, 50, 78, 100, 120 and 150 Hz with 256×256 pixel resolution. Limitations in design and suggestions for improvement of the scanner performance are discussed. - Author(s): N.I. Maniscalco ; K.D. Ko ; K.C. Toussaint ; W.P. King
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 314 –316
- DOI: 10.1049/mnl.2011.0708
- Type: Article
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The design, fabrication and characterisation of a microcantilever having two back-to-back light-emitting Pt–Si Schottky diodes fabricated near the cantilever free end is reported. Visible light is emitted from the Schottky barrier junctions under reverse bias. The diodes breakdown at a voltage of 100 V and during breakdown the diodes emit light with a peak wavelength near 710 nm. This approach for integrating a light-emitting Schottky diode onto a microcantilever could be used to introduce light into scanning probe or sensing measurements. - Author(s): M. Pellegrino ; P. Orsini ; M. Pellegrini ; P. Baschieri ; F. Dinelli ; D. Petracchi ; E. Tognoni ; C. Ascoli
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 317 –320
- DOI: 10.1049/mnl.2011.0670
- Type: Article
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Scanning ion conductance microscopy (SICM) is a scanning probe microscopy particularly suitable for the investigation of living biological specimens due to its low invasivity. Recently, this technique has been used not only to perform 3D-imaging, but also to stimulate and guide neuronal growth cones. In particular, it has been demonstrated that one can guide the cone growth for tens of micrometres by means of recurrent and non-contact SICM scanning along a defined line, with a pipette having an internal hydrostatic pressure. Accurate measurements of the mechanical forces acting on the cell membrane in these stimulation protocols are essential to explain the biological mechanisms involved. Herein a setup specifically developed for this purpose, combining together SICM, atomic force microscopy (AFM) and inverted optical microscopy is described. In this configuration, a SICM pipette can be approached to an AFM cantilever while monitoring the cantilever deflection as a function of the hydrostatic pressure applied to the pipette and the relative distance. In this way, one can directly measure mechanical forces down to 20 pN. The same apparatus is thus sufficient to calibrate a given pipette and immediately use it to study the hydrostatic pressure effects on living cells. - Author(s): A.J. Haemmerli ; R.T. Nielsen ; W. Kundhikanjana ; N. Harjee ; D. Goldhaber-Gordon ; Z.X. Shen ; B.L. Pruitt
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 321 –324
- DOI: 10.1049/mnl.2011.0679
- Type: Article
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New scanning probes suitable for microwave impedance microscopy (MIM) measurements on any scanning platform using a piezoactuator are presented. The authors microfabricated piezoresistive cantilevers integrated with low-impedance, electrically shielded transmission lines to enable simultaneous topographical and electrical scanning probe microscopy. The probes provide topography feedback with nanometre vertical resolution for samples or setups where laser detection is not feasible or desirable. MIM is a scanning probe technique that uses the interaction of a gigahertz electrical signal with a sample, and yields a conductivity map of the sample at the nanoscale. The proposed design exhibits vertical displacement resolution of 3.5 nm in a measurement bandwidth from 1 to 10 kHz. The capacitance between shield and inner conductors measured with an impedance analyser is 9.5 pF and the trace resistance is 32 Ω. Sample location and topographic scanning capabilities using the self-sensing piezoresistor are demonstrated. - Author(s): J. Rouhi ; S. Mahmud ; S.D. Hutagalung ; S. Kakooei
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 325 –328
- DOI: 10.1049/mnl.2011.0658
- Type: Article
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The mutual and individual effects of ambient humidity, applied voltage and tip speed on nanooxide masks fabricated by atomic force microscopy were investigated in a statistical system. A response surface methodology and central composite design were used to determine the optimum conditions for nanooxidation. The effects of simultaneous changes in the three independent variables on the thickness of the nanooxide mask were investigated; each variable was found to significantly contribute to the oxide thickness. The experimental results obtained were fitted to a quadratic equation model by multiple regression analysis of all of the response variables studied. The optimum nanooxidation conditions were found to be an ambient humidity of 63.81%, an applied voltage of 7.5 V, and a tip speed of 0.20 µm/s. Application of these conditions resulted in an experimental oxide thickness of 3.14 nm, which is in very close agreement with that predicted by the model. Nanogap electrodes fabricated by the proposed method were very smooth and had straight edges, indicating that the technique has a great potential for the fabrication of nanoelectronic devices. - Author(s): O. Ozcan and M. Sitti
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 329 –333
- DOI: 10.1049/mnl.2011.0671
- Type: Article
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A comprehensive model is proposed that can be used to select a proper conductive atomic force microscopy (CAFM) probe for use in stable scanning tunnelling microscopy (STM) operation. This type of operation mode could be useful for scanning and patterning heterogeneous surfaces with both conductive and insulating parts using electrical principles in a non-contact fashion. The model includes elastic contact deformation, intermolecular forces, electrostatic attraction and tunnelling current generation between the tip and the sample and the snap-into contact criterion of the probe. Using the model, snap-into contact distances of the probes with varying stiffness values under different bias voltages are found, and is verified with experiments. It is shown that, for a given sample and tip materials, an optimal bias voltage for STM operation with CAFM cantilevers exists. The results also show that, to successfully utilise CAFM probes as STM end-effectors, there is a minimum normal stiffness limit for a given bias voltage. For operation on metal surfaces using metal-coated probes with tip radius values smaller than 50 nm, the model predicts that probes with high stiffness values (>24 N/m) enable both STM and AFM operations reliably with potential resolution reduction in AFM force sensing. The model also implies that probes with longer tips are better for minimising the electrostatic attraction between the cantilever and the substrate. The model would help researchers to select proper CAFM probes, which could enable simultaneous AFM and STM imaging and manipulation capabilities for tip-based nanofabrication applications. - Author(s): W. Hu ; J.A. Bain ; D.S. Ricketts
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 334 –336
- DOI: 10.1049/mnl.2011.0678
- Type: Article
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In this Letter, a combination of conductive atomic force microscopy (AFM) and scanning tunnelling microscopy (STM) with a compliant cantilever is used to electrically probe oxidised TiO2−x nanostructures in situ. In STM mode, both the written width and the effective resistivity of material in the written line increase with write bias. At low writing voltages (∼3.5 V), the STM written lines are narrow (30 nm), but they are not resistive enough to allow patterns with a 1–2 µm perimeter to provide electrical isolation above 10 MΩ. Raising the bias to 8.5 V during writing allows similar structures to provide isolation of better than 250 MΩ. The resistivity in the lines written at the latter with high bias is 28 Ω m. From electrical estimates, the oxidation appears to go through the thickness at all voltages, but is more chemically incomplete (larger value of x) at low voltage. The data are not consistent, with a small amount of metallic Ti remaining under the written mark, that is, partial penetration of the oxidation. The thickness of this Ti layer would have to be unphysically small (1 million times smaller than an atomic layer thickness) to allow this interpretation. - Author(s): C. Ingrosso ; E. Sardella ; S.S. Keller ; M. Striccoli ; A. Agostiano ; A. Boisen ; M.L. Curri
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 337 –342
- DOI: 10.1049/mnl.2011.0673
- Type: Article
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In this Letter, a solution-based approach has been used for chemically immobilising oleic acid (OLEA)-capped TiO2 nanocrystals (NCs) on the surface of microcantilevers formed of SU-8, a negative tone epoxy photoresist. The immobilisation has been carried out at room temperature, under visible light, in ambient atmosphere and without applying any external driving force or chemical activation of the epoxy photoresist surface. Atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy investigation demonstrate the spontaneous chemical anchoring of the organic-coated TiO2 NCs on the microcantilevers, which resulted in a highly interconnected nanoporous multilayer structure. The chemical and morphological characterisation shows that the immobilised NCs do not change either their pristine morphology or the chemical structure after binding. Spectroscopic investigation infers that the TiO2 NCs chemically bind through the free and highly reactive epoxy groups located on the epoxy photoresist surface by means of the OLEA capping molecules. Finally, the results show that the fabrication procedure of the microcantilevers has not been affected by the immobilisation protocol. The capability of the immobilised TiO2 NCs to generate surface-reactive hydroxyl radicals under UV-light irradiation has a good potential for detecting families of organic compounds when integrating the modified microcantilevers in electronic noses. - Author(s): G. Rius and M. Yoshimura
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 343 –347
- DOI: 10.1049/mnl.2011.0596
- Type: Article
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A comparative study for the evaluation of carbon nanotube (CNT) functionalised tips as an interface for the determination of electrical and electronic properties of the surface of materials and devices is presented. The results of current spectroscopy measurements, complemented with force–current testing, reveal a strong dependence of the establishment of tip–sample electrical contact with environmental conditions and procedure. Multiwalled CNT-mediated measurements are compared with the results by commonly used as-purchased probes, metal-coated and Si probes, upon an inert and low-resistance Au substrate. The introduction of CNTs in the tip vicinity represents a drastic advance in the conduction capability as compared with the silicon probes. Despite a certain reduction of conduction as compared with metal-coated probes, a significant improvement of tip apex durability, together with, non-invasive mechanical contact to the sample is demonstrated. The present multiwalled CNT probes are proposed as an ideal element for electronic studies at the nanometre scale by atomic force microscopy.
Editorial
Temperature compensation in integrated CMOS-MEMS scanning probe microscopes
Two-dimensional cantilever array with varying spring constants and tip radii for life-science applications
Fabrication and characterisation of piezoelectric microcantilever probe
Design of a compact serial-kinematic scanner for high-speed atomic force microscopy: an analytical approach
Microcantilever with integrated light-emitting Schottky barrier avalanche breakdown diodes
Integrated SICM-AFM-optical microscope to measure forces due to hydrostatic pressure applied to a pipette
Low-impedance shielded tip piezoresistive probe enables portable microwave impedance microscopy
Optimisation of nanooxide mask fabricated by atomic force microscopy nanolithography: a response surface methodology application
Modelling of conductive atomic force microscope probes for scanning tunnelling microscope operation
In situ quantification of electrical isolation in STM-fabricated TiOx nanostructures
Surface chemical functionalisation of epoxy photoresist-based microcantilevers with organic-coated TiO2 nanocrystals
Interfacing resistances in conducting probe atomic force microscopy with carbon nanotubes functionalised tips
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- Author(s): Yiming M. Fu ; Haiqiang Q. Zhou ; Pu Zhang
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 348 –352
- DOI: 10.1049/mnl.2011.0689
- Type: Article
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Considering the transverse shear deformation, geometric nonlinearity and the surface effects as well as the non-local effects, the nonlinear free vibration of nanowires is studied in this Letter. On the basis of the Timoshenko beam theory and Hamilton's principle, the nonlinear dynamics equations and corresponding boundary conditions of nanowires are derived. Then, the Galerkin method and the incremental harmonic balance method are adopted to solve the nonlinear equations. In numerical examples, the effects of the transverse shear deformation, geometric nonlinearity, surface effects as well as the non-local effects on the nonlinear amplitude–frequency response of nanowires are discussed. - Author(s): Lu Fang and Wen Jun Li
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 353 –356
- DOI: 10.1049/mnl.2011.0530
- Type: Article
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A flake-like MnCO3 film has been successfully synthesised by the hydrothermal method, with high gravity field using 0.5 mol/L MnCl2 and 5 mol/L CO(NH)2 as precursor at 120°C for 30 min in the aqueous solution–bromobenzene system. The effects of the relative centrifugal field and the reaction temperature on the formation of flake-like MnCO3 film were examined. The resultant samples were characterised by X-ray diffraction, Fourier transform infrared, FE-scanning electron microscopy and thermogravimetric differential thermal analysis. The results reveal that low temperature and high gravity field are favourable for the formation of flake-like MnCO3 film. The hierarchical Mn3O4 were obtained after calcinations of the flake-like MnCO3 film at 700°C for 1 h in air. - Author(s): Huihua Jing ; Xiaoqing Chen ; Xinyu Jiang
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 357 –359
- DOI: 10.1049/mnl.2011.0604
- Type: Article
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Bismuth oxide (Bi2O3) microtetrahedrons and cubes were synthesised in large quantities by a chemical precipitation and refluxing method with BiCl3 and NaOH as reactants in alcohol–water systems. The products were characterised by X-ray powder diffraction (XRD), field emission-scanning electron microscope (FESEM), energy-dispersive X-ray spectroscope (EDS) and SEM. XRD analyses showed that the as-prepared Bi2O3 was body-centred cubic (bcc) (γ) phase and had a high degree of crystallinity. FESEM and SEM micrographs indicated that tetrahedral Bi2O3 with the edge length of 1–5 µm was formed. The morphology of the final products changed into microcubes by increasing the amount of dispersant. The result of the influence of reaction temperature on products revealed that the pure-phase γ-Bi2O3, as well as well-defined tetrahedron, was obtained at the temperature ≥75°C. - Author(s): Jun Li ; Bin Kang ; Shuquan Chang ; Yaodong Dai
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 360 –362
- DOI: 10.1049/mnl.2011.0609
- Type: Article
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Plasmonic nanoparticles including nanogold and nanosilver were prepared from a convenient gamma radiation route. Biocompatible copolymer chitosan oligomer was used as a template for nanoparticle growing. The obtained gold and silver nanoparticle colloids exhibited excellent water solubility and stability and these nanoparticles were well separated and uniform in size. They exhibited bright scattering light in a dark field owing to the surface plasmon resonance effect and could be easily detected even in a single-particle state. When cultured with cells, they would be internalised into cells and their intense scattering light made cells easily identifiable. These plasmonic nanoparticles obtained from the gamma radiation route could be used as promising contrast agents for multi-colour dark field cell imaging. - Author(s): Jun wei Li ; Xiang feng Wu ; Xin hua Xu
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 363 –365
- DOI: 10.1049/mnl.2011.0647
- Type: Article
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Uniform and oriented ZnO nanorod arrays on the surface of hollow glass microspheres (HGMs) were fabricated by using a seed growth process in aqueous solution of zinc nitrate and hexamethylenetetramine at low temperature. The structure and morphology of as-obtained ZnO nanorod array-coated hollow glass microsphere (HGM/ZnO) composites were analysed by using X-ray diffraction and scanning electron microscopy. The results showed that all the HGMs were coated with a well-aligned layer of ZnO nanorod arrays and the ZnO nanorods possessed relatively uniform hexagonal rod structures and stood perpendicular. Moreover, the ZnO nanorod arrays were affected by a variety of growth conditions such as the growth solution concentration and the solution temperature. - Author(s): L. Nikzad ; T. Ebadzadeh ; M.R. Vaezi ; A. Tayebifard
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 366 –369
- DOI: 10.1049/mnl.2012.0079
- Type: Article
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The preparation of boron carbide nanoparticles was investigated by coupling a highly exothermic B2O3–Mg thermite reaction with a weakly exothermic B4C formation reaction. An experimental study for the formation of B4C nanoparticles was conducted by combustion synthesis in the mode of thermal explosion. The mixture of B2O3:Mg:C with stoichiometry 2:7:1 was milled for 1, 3, 6, 12, 24 and 36 h. The milled powders up to 12 h were used for the combustion reaction. The combustion reactions were carried out in an inert atmosphere (Ar) at 900°C. The samples are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD analysis of all samples after combustion indicated that the main phase was MgO along with Mg3(Bo3)2 and B4C as secondary phases. The XRD analysis of samples after leaching of the combustion product detected boron carbide as a main phase and unreacted graphite as minor phase, while the graphite was the least for products of 12 h milled powders. The TEM image of this sample showed nanometric crystallite of less than 60 nm. - Author(s): Jianan Zhang ; Qing Liu ; Wenlong Yang ; Beibei Yang ; Mingyuan Wu ; Jianjun Yang ; Qingyun Wu ; Bo Wu ; Jizhi Lin
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 370 –372
- DOI: 10.1049/mnl.2012.0072
- Type: Article
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This Letter describes a new approach for synthesis of flower-like silver nanostructured particles by using a polystyrene (PS) template. Ag nanoparticles (NPs) were prepared successively by the addition of AgNO3 aqueous solution to the dispersion, adsorption of Ag+ ions on the surfaces of a functional PS template and then the reduction of Ag+ ions to flower-like silver NPs by aqueous hydrazine hydrate. The nanostructured particles are characterised by UV–visible spectroscopy, transmission electron microscopy and X-ray diffraction. The results showed that the size of Ag NPs was mainly between 60 and 150 nm with flower-like morphology. The Ag NPs showed good catalytic properties in the oxidation–reduction reaction of methylene blue by NaBH4. - Author(s): Jie Chen ; Zaiyin Huang ; Cuiwu Lin
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 373 –375
- DOI: 10.1049/mnl.2012.0126
- Type: Article
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CdS hollow nanospheres have been successfully synthesised in the water–ethylene glycol system at room temperature. It is speculated that the formation of hollow nanospheres is an Ostwald ripening process. More importantly, the growth process of the CdS hollow nanospheres has been investigated through microcalorimetry combined with photoluminescence spectra and scanning electron microscope for the first time. The analysis result further proves the formation mechanism of CdS hollow nanospheres. - Author(s): Yiin-Kuen Fuh ; Li-Chih Lien ; Jason S.C. Jang
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 376 –379
- DOI: 10.1049/mnl.2012.0161
- Type: Article
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A comparative study utilising both continuous near-field electrospinning (CNFES) and conventional electrospinning processes of electrospun polyvinylidene fluoride (PVDF)-based membranes (EPMs) is presented in this Letter. The fibre morphology and average fibre diameter (AFD) of the EPMs are observed by scanning electron microscopy. Differential scanning calorimetry (DSC) is used to compare the possible modifications in crystal structure and thermal properties. Fourier transform infrared spectroscopy is used to study the crystalline isomers of PVDF EPMs. Results indicate that EPMs prepared by CNFES exhibit slightly lower relative intensities at the infrared absorption bands than the conventional electrospinning counterparts, owing to its smaller size of crystallite. Moreover, the CNFES electrospun fibres are revealed to have relatively higher crystallinity of 40.78%, as compared with conventional ones of 33.72%. However, DSC results indicate that both CNFES and conventional EPMs share similar thermographs in endothermic peaks extending from 156 to 174°C, despite the significant differences in AFD. Finally, the critical length of PVDF nanofibres is characterised experimentally and theoretical prediction of r∝z−0.5 is in well agreement with the experimental observations of r∝z−0.51. - Author(s): M. Eskandari ; M. Yeganeh ; M. Motamedi
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 380 –383
- DOI: 10.1049/mnl.2012.0162
- Type: Article
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Corrosion resistance of nanocrystalline 316L stainless steel was compared with a coarse-grained (CG) one using potentiodynamic polarisation and electrochemical impedance spectroscopy methods and electron microscopy. The results showed that the corrosion resistance of nanocrystalline 316L stainless steel was higher than CG stainless steel. It was attributed to unstable passive layer on CG 316L stainless steel, which could be removed in a corrosive medium. The lower grain size facilitated fast diffusion of Cr and formation of passive layer. Nanocrystalline 316L stainless steel showed a relatively stable current density in anodic potentials, which was related to the higher corrosion resistance of nanocrystalline 316L stainless steel. - Author(s): Junbo Yang ; Zhenrong Zhang ; Shenli Chang ; Honghui Jia ; Xueao Zhang
- Source: Micro & Nano Letters, Volume 7, Issue 4, p. 384 –387
- DOI: 10.1049/mnl.2012.0104
- Type: Article
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A double-layer grating design particularly suitable for triplexers is presented. It consists of two silicon-on-insulator planar waveguide gratings, where the upper grating is used to couple and split 1310 and 1490 nm signal, and transmits along the opposite direction. The coupling efficiency is about 88 and 84%. The crosstalk can reach up to −21 and −11 dB. However, the 1550 nm signal light almost passes through the upper layer and then is coupled by the lower grating. The coupling efficiency is about 79%. The design is validated by simulation, which shows excellent performance in terms of wavelength bandwidth, crosstalk, coupling efficiency as well as incident angle and so on.
Nonlinear free vibration of nanowires including size effects
Hydrothermal synthesis of flake-like MnCO3 film under high gravity field and their thermal conversion to hierarchical Mn3O4
Controlled synthesis of bismuth oxide microtetrahedrons and cubes by precipitation in alcohol–water systems
Gamma radiation synthesis of plasmonic nanoparticles for dark field cell imaging
Preparation and characterisation of ZnO nanorod array-coated hollow glass microsphere composites
Effect of milling on the combustion synthesis of ternary system B2O3, Mg and C
Facile fabrication and catalytic property of ‘flower-like’ silver nanoparticles
One-step synthesis and growth process of CdS hollow spheres
Comparative study of polyvinylidene fluoride nanofibrous membranes prepared by continuous near-field and conventional electrospinning processes
Investigation in the corrosion behaviour of bulk nanocrystalline 316L austenitic stainless steel in NaCl solution
Compact double-layer waveguide grating triplexer based on silicon-on-insulator
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