scholarly journals Au Doping ZnO Nanosheets Sensing Properties of Ethanol Gas Prepared on MEMS Device

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 945
Author(s):  
Yempati Nagarjuna ◽  
Yu-Jen Hsiao
Keyword(s):  
Gas Sensing ◽  
Micro Electro Mechanical System ◽  
Operating Conditions ◽  
Structural Morphology ◽  
X Ray ◽  
Zno Nanostructure ◽  
Zno Nanosheets ◽  
Different Temperatures ◽  
Doped Zno ◽  
Mems Device

Sensitivity of the Micro Electro Mechanical System (MEMS) device ZnO nanosheets sensor and the Au doped ZnO nanosheets sensor has been investigated. The ZnO samples have been prepared using Hydrothermal synthesis at 90 °C. The prepared ZnO nanostructure is tested for structural morphology and crystallinity properties. The elemental analysis of the ZnO sample and Au–ZnO samples are tested by using Energy Dispersive X-ray Spectroscopy (EDS) spectrum analysis. MEMS device microheater is designed and prepared for testing the sensitivity of Ethanol gas. Thermal properties of the MEMS microheater is studied for better gas testing at different temperatures. Both the ZnO nanosheets sensor and Au doped ZnO nanosheets sensor are tested using Ethanol gas, and the gas concentrations are taken to be 15, 30, 45, and 60 ppm at 300 °C. The gas sensing response of pure ZnO nanosheets tested for ethanol gas at 60 ppm showed 20%, while the Au–ZnO nanosheets showed 35%, which is increased by 15% at similar operating conditions.

scholarly journals Curvature Dependent Electrostatic Field in the Deformable MEMS Device: Stability and Optimal Control

2020 ◽  
Vol 11 (1) ◽  
pp. 35-54
Author(s):  
Paolo Di Barba ◽  
Luisa Fattorusso ◽  
Mario Versaci
Keyword(s):  
Optimal Control ◽  
Electrostatic Field ◽  
Stable Equilibrium ◽  
Micro Electro Mechanical System ◽  
Operating Conditions ◽  
Electric Voltage ◽  
External Voltage ◽  
Device Stability ◽  
Equilibrium Configurations ◽  
Mems Device

AbstractThe recovery of the membrane profile of an electrostatic micro-electro-mechanical system (MEMS) device is an important issue because, when applying an external voltage, the membrane deforms with the consequent risk of touching the upper plate of the device (a condition that should be avoided). Then, during the deformation of the membrane, it is useful to know if this movement admits stable equilibrium configurations. In such a context, our present work analyze the behavior of an electrostatic 1D membrane MEMS device when an external electric voltage is applied. In particular, starting from a well-known second-order elliptical semi-linear di erential model, obtained considering the electrostatic field inside the device proportional to the curvature of the membrane, the only possible equilibrium position is obtained, and its stability is analyzed. Moreover, considering that the membrane has an inertia in moving and taking into account that it must not touch the upper plate of the device, the range of possible values of the applied external voltage is obtained, which accounted for these two particular operating conditions. Finally, some calculations about the variation of potential energy have identified optimal control conditions.

scholarly journals Facile Microemulsion Synthesis of Vanadium-Doped ZnO Nanoparticles to Analyze the Compositional, Optical, and Electronic Properties

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 821 ◽  
Author(s):  
H.S. Ali ◽  
Ali Alghamdi ◽  
G. Murtaza ◽  
H.S. Arif ◽  
Wasim Naeem ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Attenuated Total Reflection ◽  
Lattice Parameters ◽  
Average Particle ◽  
Structural Morphology ◽  
Wurtzite Phase ◽  
X Ray ◽  
Doped Zno

In this work, microemulsion method has been followed to synthesize vanadium-doped Zn1−xVxO (with x = 0.0, 0.02, 0.04, 0.06, 0.08, and 0.10) nanoparticles. The prepared samples are characterized by several techniques to investigate the structural, morphology, electronic, functional bonding, and optical properties. X-ray diffractometer (XRD) analysis confirms the wurtzite phase of the undoped and V-doped ZnO nanoparticles. Variation in the lattice parameters ensures the incorporation of vanadium in the lattice of ZnO. Scanning electron microscopy (SEM) shows that by increasing contents of V ions, the average particle size increases gradually. X-ray Absorption Near Edge Spectroscopy (XANES) at the V L3,2 edge, oxygen K-edge, and Zn L3,2 edge reveals the presence and effect of vanadium contents in the Zn host lattice. Furthermore, the existence of chemical bonding and functional groups are also asserted by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). UV–Visible analysis shows that by increasing V+ contents, a reduction up to 2.92 eV in the energy band gap is observed, which is probably due to an increase in the free electron concentration and change in the lattice parameters.

scholarly journals Mg-doped and chemo-thermally treated ZnO nanoflowers for ethanol sensing

2021 ◽  
Author(s):  
Santanu Maity ◽  
P.P Sahu ◽  
Tiju Thomas
Keyword(s):  
Gas Sensing ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Wide Range ◽  
Doped Zno ◽  
Ethanol Sensing ◽  
Better Than ◽  
Mg Doped

Abstract ZnO nanostructures are promising for a wide range of applications, including gas sensors. Ethanol sensing using ZnO remains unexplored though. In this paper, we report ethanol-sensing using un-doped ZnO nano flowers and Mg doped ZnO nano flowers. These are grown using a rather simple chemo-thermal process, making this a plausibly scalable technology. To study the structural and morphological properties of undoped ZnO and Mg doped ZnO nanoflowers, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) are carried out. Ethanol sensing properties of undoped ZnO and Mg doped ZnO nanoflower devices are investigated toward different ethanol concentration (concentration range of 1–600 ppm at 100°C–200°C). Our findings show that 15% Mg doped ZnO nano flower is better than ZnO nano flower for ethanol gas-sensing applications.

scholarly journals Facile Hydrothermal Synthesis of Two-Dimensional Porous ZnO Nanosheets for Highly Sensitive Ethanol Sensor

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Lai Van Duy ◽  
Nguyen Hong Hanh ◽  
Dang Ngoc Son ◽  
Pham Tien Hung ◽  
Chu Manh Hung ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Fast Response ◽  
Two Dimensional ◽  
Ethanol Sensor ◽  
X Ray ◽  
Transmission Electron ◽  
Porous Nanosheets ◽  
Composition And Structure ◽  
Zno Nanosheets

Two-dimensional porous ZnO nanosheets were synthesized by a facile hydrothermal method for ethanol gas-sensing application. The morphology, composition, and structure of the synthesized materials were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, powder X-ray diffraction, and high-resolution transmission electron microcopy. Results showed that the synthesized ZnO materials were porous nanosheets with a smooth surface and a thickness of 100 nm and a large pore size of approximately 80 nm. The as-prepared nanosheets, which had high purity, high crystallinity, and good dispersion, were used to fabricate a gas sensor for ethanol gas detection at different operating temperatures. The porous ZnO nanosheet gas sensor exhibited a high response value of 21 toward 500 ppm ethanol at a working temperature of 400°C with a reversible and fast response to ethanol gas (12 s/231 s), indicating its potential application. We also discussed the plausible sensing mechanism of the porous ZnO nanosheets on the basis of the adopted ethanol sensor.

scholarly journals Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Murtaza Saleem ◽  
Shahid Atiq ◽  
Shahid M. Ramay ◽  
Asif Mahmood ◽  
Saadat A. Siddiqi ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Electron Microscopic ◽  
Structural Morphology ◽  
X Ray ◽  
Phase Pure ◽  
Doped Zno ◽  
Mn Doped

Zn0.95Mn0.05O nanostructures were synthesized using sol gel derived autocombustion technique. As-burnt samples were thermally annealed at different temperatures (400, 600, and 800°C) for 8 hours to investigate their effect on structural morphology and magnetic behavior. X-ray diffraction and scanning electron microscopic studies demonstrated the improvement in crystallinity of phase pure wurtzite structure of Mn doped ZnO with variation of annealing temperature. Energy dispersive X-ray elemental compositional analysis confirmed the exact nominal compositions of the reactants. Electrical resistivity measurements were performed with variation in temperature, which depicted the semiconducting nature similar to parent ZnO after 5 at% Mn doping. Magnetic measurements by superconducting quantum interference device detected an enhanced trend of ferromagnetic interactions in thermally annealed compositions attributed to the improved structural morphology and crystalline refinement process.

Alcohol Sensing Properties of SnO2/CNT Nanocomposites Synthesized by Microwave-Assisted Process

2016 ◽  
Vol 675-676 ◽  
pp. 85-88
Author(s):  
Nalita Sawangjit ◽  
Wicharn Techitdheera ◽  
Wisanu Pecharapa
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Structural Morphology ◽  
X Ray ◽  
Multi Wall Carbon Nanotubes ◽  
Microwave Assisted ◽  
Sensing Sensitivity ◽  
Scanning Electron

SnO2/CNT nanocomposites were synthesized via microwave-assisted process using SnCl4·5H2O as a starting precursor and UV-treated multi-wall carbon nanotubes (MWCNTs) as scaffolds. The concentration of SnCl4 was varied in the range of 0.01-0.05 M. Effect of precursor concentration on their physical properties and micro structural morphology were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD results indicate that the as-synthesized composites are the mixture of two separated phases including SnO2 and MWCNT. SEM images indicate that the surfaces of MWCNT are thoroughly covered with SnO2 nanoparticles. Comparative gas sensing result reveals that the prepared hybrid SnO2/MWCNT composites exhibit much higher sensing sensitivity and recovery property in detecting alcohol gas at room temperature than the bare SnO2.

Synthesis of Al Doped ZnO with a Novel Rice Microstructure by Hydrothermal Process and Analysis of their Gas Sensing Properties

2014 ◽  
Vol 809-810 ◽  
pp. 724-730
Author(s):  
Zan Li ◽  
Wei Qin ◽  
Xiao Hong Wu
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Hexagonal Wurtzite Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Doped Zno ◽  
Hydrothermal Approach

Al-doped ZnO (AZO) powers with a novel rice-like morphology have been successfully synthesized through a simple and efficient hydrothermal approach, the products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray analyzer and transmission electron microscopy (TEM). It showed that all the samples presented an hexagonal wurtzite structure of high crystallinity, and the microstructure was composed of numerous dumbbells. Furthermore, the heater gas sensors were fabricated and an investigation of gas sensing properties has been conducted. The sensors showed good selectivity to ethanol comparing with NH3, SO2, CO and HCHO and possible mechanism was discussed. The Sensors based AZO powers exhibited high response values, reproducible response-recovery to ethanol 50-1800 ppm at 332°C.

Corrigendum to ‘Ba-doped ZnO nanostructure: X-ray line analysis and optical properties in visible and low frequency infrared’ [Ceram. Int. (2016) 12860–12867]

2016 ◽  
Vol 42 (14) ◽  
pp. 16436
Author(s):  
Reza Zamiri ◽  
Hossein Mahmoudi Chenari ◽  
H.F. Moafi ◽  
Mehdi Shabani ◽  
S.A. Salehizadeh ◽  
...  
Keyword(s):  
Optical Properties ◽  
Low Frequency ◽  
X Ray ◽  
Zno Nanostructure ◽  
Doped Zno ◽  
Line Analysis

Gallium and Nitrogen Co-Doped ZnO Thin Films by Pulsed Laser Deposition

2008 ◽  
Vol 368-372 ◽  
pp. 322-325
Author(s):  
G.X. Liu ◽  
F.K. Shan ◽  
Byoung Chul Shin ◽  
Won Jae Lee
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Zno Thin Films ◽  
X Ray ◽  
Atomic Force ◽  
Different Temperatures ◽  
Doped Zno ◽  
Co Doped

Pulsed laser deposition (PLD) technique is a very powerful method for fabricating various oxide thin films due to its native merits. In this study, gallium and nitrogen co-doped ZnO thin films (0.1 at.%) were deposited at different temperatures (100-600°C) on sapphire (001) substrates by using PLD. X-ray diffractometer, atomic force microscope, spectrophotometer, and spectrometer were used to characterize the structural, the morphological and the optical properties of the thin films. Hall measurements were also carried out to identify the electrical properties of the thin films.

The Morphology of Corrosion Products in FeAl Alloys after Heat-Resistance Tests at Different Temperatures

2015 ◽  
Vol 227 ◽  
pp. 409-412 ◽  
Author(s):  
Agnieszka Fornalczyk ◽  
Janusz Cebulski ◽  
Pasek Dorota
Keyword(s):  
Heat Resistance ◽  
Surface Condition ◽  
Intermetallic Phases ◽  
Passive Layer ◽  
Operating Conditions ◽  
Corrosion Products ◽  
X Ray ◽  
Physico Chemical ◽  
Different Temperatures ◽  
Resistance Tests

The alloys based on intermetallic phases involving Al belong to a new group of heat-resistant materials. Their physico-chemical and mechanical properties allow to apply them in the operating conditions in corrosive environment and elevated temperature. Research conducted for many years has shown that these materials can work at temperature up to 1100°C without degradation of their occurrence in the environment containing oxygen and sulphur. Heat resistance of these materials is provided by forming the Al2O3 passive layer on the surface. This layer is a protective barrier, which hinders the oxygen diffusion into the surface. This paper presents the morphology of passive Al2O3 layer depending on the temperature of its formation. The study allows to define the surface condition for corrosion products carried out using scanning electron microscopy together with EDS X-ray microanalysis.

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