scholarly journals MOBILE ACETONE SENSOR

2020 ◽  
Author(s):  
D. Susla
Keyword(s):  
Intelligent Systems ◽  
Annealing Temperature ◽  
Operating Temperature ◽  
Mobile Sensors ◽  
Optimal Operating ◽  
Future Directions ◽  
X Ray ◽  
Zinc Oxide Films ◽  
Voc Sensor ◽  
Acetone Sensor

The aim of this work is to develop mobile sensors for acetone based on metal oxide for their subsequent use in the development of devices for monitoring health status. The following research methods were used in the work: measuring the sensitivity of sensor samples on the film thickness and annealing temperature; removal of dependences of sensitivity, selectivity and detection limits on operating temperature; studying the morphology of sensor samples using X-ray diffractometry and field emission scanning electron microscopy. An acetone sensor was developed on the basis of nanostructured thin zinc oxide films, its sensitivity was determined at various temperatures, as a result of which the optimal operating temperature of the sensor was about 400 ° C. The sensitivity value of the ZnO gas sensor was more than 26.5% at 1000 ppm, 65% at 500 ppm and 5% at 300 ppm acetone. Possible future directions of development are the development of multisensor VOC sensor systems for implementation in wireless intelligent systems for monitoring the health of the population.

scholarly journals Effects of Niobium-Loading on Sulfur Dioxide Gas-Sensing Characteristics of Hydrothermally Prepared Tungsten Oxide Thick Film

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Viruntachar Kruefu ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Spin Coating ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sensor Response ◽  
X Ray Diffraction ◽  
Optimal Operating ◽  
Impregnation Process ◽  
X Ray ◽  
Transmission Electron ◽  
Sensing Characteristics

Nb-loaded hexagonal WO3nanorods with 0–1.0 wt% loading levels were successfully synthesized by a simple hydrothermal and impregnation process and characterized for SO2sensing. Nb-loaded WO3sensing films were produced by spin coating on alumina substrate with interdigitated gold electrodes and annealed at 450°C for 3 h in air. Structural characterization by X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis showed that spherical, oval, and rod-like Nb nanoparticles with 5–15 nm mean diameter were uniformly dispersed on hexagonal WO3nanorods with 50–250 nm diameter and 100 nm–5 µm length. It was found that the optimal Nb loading level of 0.5 wt% provides substantial enhancement of SO2response but the response became deteriorated at lower and higher loading levels. The 0.50 wt% Nb-loaded WO3nanorod sensing film exhibits the best SO2sensing performances with a high sensor response of ~10 and a short response time of ~6 seconds to 500 ppm of SO2at a relatively low optimal operating temperature of 250°C. Therefore, Nb loading is an effective mean to improve the SO2gas-sensing performances of hydrothermally prepared WO3nanorods.

Synthesis of Au Nanoparticles Functionalized 1D α-MoO3 Nanobelts and Their Gas Sensing Properties

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850115 ◽  
Author(s):  
Liwei Wang ◽  
Shaopeng Wang ◽  
Hao Fu ◽  
Yinghui Wang ◽  
Kefu Yu
Keyword(s):  
Electron Microscope ◽  
Au Nanoparticles ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Molecular Probe ◽  
Optimal Operating ◽  
Au Nps ◽  
X Ray ◽  
Sensing Properties ◽  
Optimal Operating Temperature

A novel sensor material of Au nanoparticles (NPs) functionalized 1D [Formula: see text]-MoO3 nanobelts (NBs) was fabricated by a facile lysine-assisted approach. The obtained Au/[Formula: see text]-MoO3 product was characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray (EDX), and X-ray photoelectron spectra (XPS). Then, in order to investigate the gas sensing performances of our samples, a comparative gas sensing study was carried out on both the [Formula: see text]-MoO3 NBs before and after Au NPs decoration by using ethanol vapor as the molecular probe. The results turned out that, after the functionalization of Au NPs, the sensor exhibited improved gas-sensing characteristics than the pure [Formula: see text]-MoO3, such as response and recovery time, optimal operating temperature (OT) and excellent selectivity. Take for example 200[Formula: see text]ppm of ethanol, the response/recovery times were 34[Formula: see text]s/43[Formula: see text]s and 5.7[Formula: see text]s/10.5[Formula: see text]s, respectively, while the optimal operating temperature (OT) was lower to 200[Formula: see text]C rather than 250[Formula: see text]C. Besides, the functionalized sensor showed a higher response to ethanol at 200[Formula: see text]C, and response was 1.6 times higher than the pure MoO3. The mechanism of such improved sensing properties was interpreted, which might be attributed to the spillover effect of Au NPs and the electronic metal-support interaction.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

scholarly journals Effects of Thermal Annealing on the Properties of Zirconium-Doped MgxZn1−XO Films Obtained through Radio-Frequency Magnetron Sputtering

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 373
Author(s):  
Wen-Yen Lin ◽  
Feng-Tsun Chien ◽  
Hsien-Chin Chiu ◽  
Jinn-Kong Sheu ◽  
Kuang-Po Hsueh
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Radio Frequency Magnetron ◽  
Radio Frequency Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Free Electrons ◽  
X Ray ◽  
Mg Content

Zirconium-doped MgxZn1−xO (Zr-doped MZO) mixed-oxide films were investigated, and the temperature sensitivity of their electric and optical properties was characterized. Zr-doped MZO films were deposited through radio-frequency magnetron sputtering using a 4-inch ZnO/MgO/ZrO2 (75/20/5 wt%) target. Hall measurement, X-ray diffraction (XRD), transmittance, and X-ray photoelectron spectroscopy (XPS) data were obtained. The lowest sheet resistance, highest mobility, and highest concentration were 1.30 × 103 Ω/sq, 4.46 cm2/Vs, and 7.28 × 1019 cm−3, respectively. The XRD spectra of the as-grown and annealed Zr-doped MZO films contained MgxZn1−xO(002) and ZrO2(200) coupled with Mg(OH)2(101) at 34.49°, 34.88°, and 38.017°, respectively. The intensity of the XRD peak near 34.88° decreased with temperature because the films that segregated Zr4+ from ZrO2(200) increased. The absorption edges of the films were at approximately 348 nm under 80% transmittance because of the Mg content. XPS revealed that the amount of Zr4+ increased with the annealing temperature. Zr is a potentially promising double donor, providing up to two extra free electrons per ion when used in place of Zn2+.

CuOX Films for NO2 Detection: Microstructural Characterization

2013 ◽  
Vol 481 ◽  
pp. 133-136 ◽  
Author(s):  
T.N. Myasoedova ◽  
G.E. Yalovega ◽  
N.K. Plugotarenko ◽  
M. Brzhezinskaya ◽  
V.V. Petrov ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Secondary Electron ◽  
Operating Temperature ◽  
Sol Gel ◽  
Microstructural Characterization ◽  
Temperature Treatment ◽  
Copper Oxides ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Copper oxides films as promising materials for gas sensors applications were studied. Copper oxide films were deposited onto Si/SiO2substrates using a citrate sol-gel method with the subsequent temperature treatment at 150-5000C. These films were characterized by means of secondary electron microscopy (SEM) and X-ray-absorption near-edge structure (XANES) spectroscopy. The prepared films were utilized in NO2sensors. The dependences of the NO2response on the operating temperature and NO2concentration (10-200 ppm) were investigated. The maximum NO2response was achieved for the film annealed at 2500C.

The Evaluation of TiTe2 as a Diffusion Barrier in the Formation of Low Thermal Conductivity Nanolaminates with Bi2Te3 and Sb2Te3

2010 ◽  
Vol 74 ◽  
pp. 38-47
Author(s):  
Clay Mortensen ◽  
Paul Zschack ◽  
David C. Johnson
Keyword(s):  
Thermal Conductivity ◽  
Diffusion Barrier ◽  
Self Assembly ◽  
Low Temperatures ◽  
Annealing Temperature ◽  
The Self ◽  
High Angle ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.

Influence of Microstructural Change on Damping Capacity of Mg-X%Li Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 1764-1768
Author(s):  
Joong Hwan Jun ◽  
Ki Duk Seong ◽  
Jeong Min Kim ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Single Phase ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Microstructural Change ◽  
Damping Capacity ◽  
Flexural Mode ◽  
X Ray ◽  
Α Phase ◽  
Hardness Tests ◽  
Li Content

The Effects of Li content and annealing treatment on microstructure and damping capacity for Mg-X%Li alloys have been investigated, based on experimental results from X-ray diffractometry (XRD), optical microscopy (OM), hardness tests and vibration damping tests in a flexural mode. The Mg-X%Li alloys containing Li of 3%, 8% and 13% consist of α (HCP) single phase, (α + β (BCC)) dual phases and β single phase, respectively. In as-rolled state, the damping capacity for Mg-Li alloys shows a similar level regardless of Li content. The annealing treatments at 200oC and 400οC give rise to an enhancement of damping capacity only for the Mg-3%Li and Mg-8%Li alloys containing α phase, and at the same annealing temperature, the Mg-3%Li alloy with fully α structure exhibits higher damping capacity. This result indicates that the damping capacity of Mg-Li alloys depends principally on α phase, and that the annealing treatment is necessary to improve its damping capacity.

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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