Poly(vanadium–molybdenum acid) xerogel thin films fabricated by the sol-gel process and their humidity-sensing properties

2000 ◽  
Vol 15 (12) ◽  
pp. 2653-2657 ◽  
Author(s):  
Maosong Tong ◽  
Guorui Dai ◽  
Yuanda Wu ◽  
Xiuli He ◽  
Wei Yan ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermogravimetric Analysis ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Sol Gel Process ◽  
Humidity Sensing Properties

Thermogravimetric analysis, x-ray photoelectron spectroscopy, and x-ray diffraction results and the humidity sensing properties of poly(vanadium–molybdenum acid) H2V9.5Mo2.5O32.0 · 8.8H2O xerogel thin films, which were fabricated by the sol-gel process, are described in this paper. The conductance and the capacitance of the thin films strongly depend on the relative humidity. Different electrodes have different influences on the humidity-sensing properties of the thin films.

scholarly journals Synthesis & characterization of nanostructure VO2 thin film

2021 ◽  
Vol 2070 (1) ◽  
pp. 012098
Author(s):  
P K Ojha ◽  
S K Mishra
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Cost Effective ◽  
Metallic Phase ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Abstract Vanadium dioxides are strongly correlated systems which undergo an insulator-metal transition (IMT) from a low-temperature semiconducting phase to a high-temperature metallic phase. Among them, Vanadium dioxide (VO2) undergoes IMT close to room temperature, accompanied by a structural transition resulting change of several orders of magnitude in the electrical and optical properties. Here, we present the synthesis of VO2 by sol-gel process which employs cost-effective precursors to synthesize pure phase of VO2 thin films. The synthesized thin films were characterized using an X-ray diffraction (XRD) to confirm phase purity and high resolution scanning electron microscope (HR-SEM) to study the crystallite and particle size for the synthesized films. The film’s surface was analyzed by X-ray photoelectron spectroscopy (XPS) to determine the valence state and chemical composition of vanadium dioxide.

Sol-Gel derived Bi4-xNdxTi3O12 Thin Films and Their Characterization

2002 ◽  
Vol 737 ◽  
Author(s):  
R.E. Melgarejo ◽  
M.S. Tomar ◽  
A. Hidalgo ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Complete Solid Solution ◽  
Sol Gel Process ◽  
Ferroelectric Memory ◽  
Initial Results

ABSTRACTNd substituted bismuth titanate Bi4-xNdxTi3O12 were synthesized by sol-gel process and thin films were deposited on Pt substrate (Pt/TiO2/SiO2/Si) by spin coating. Thin films, characterized by X-ray diffraction and Raman spectroscopy, shows complete solid solution up to the composition x < 1. Initial results indicate that the ferroelectric polarization increases with increasing Nd content in the film with 2Pr = 50μC/cm2 for x = 0.46, which may have application in non-volatile ferroelectric memory devices.

Synthesis and Characterizations of Strontium Substituted Hydroxyapatite Thin Films

2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Chemical Composition ◽  
Spin Coating ◽  
Phase Structure ◽  
Sol Gel ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.

Preparation of Titanium Oxide and Metal Titanates as Powders, Thin Films, and Microspheres by Novel Inorganic Sol-Gel Process

2005 ◽  
Vol 900 ◽  
Author(s):  
A. Deptuła ◽  
Kenneth C Goretta ◽  
Tadeusz Olczak ◽  
Wieslawa Lada ◽  
Andrzej G. Chmielewski ◽  
...  
Keyword(s):  
Thin Films ◽  
Ascorbic Acid ◽  
Nitric Acid ◽  
Titanium Oxide ◽  
Sol Gel ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Metal Hydroxides ◽  
X Ray ◽  
Sol Gel Process

ABSTRACTTitanium oxide and titanates based on Ba, Sr and Ca were prepared from commercial solutions of TiCl4 and HNO3. The main preparation steps for the sols consisted of elimination of chloride anions by distillation with nitric acid and addition of metal hydroxides for the titanates. Resulting sols were gelled and used to (1) prepare irregularly shaped powders by evaporation; (2) produce by a dipping technique thin films on glass, Ag, or Ti substrates; and (3) produce spherical powders (diameters <100 μm) by solvent extraction. Results of thermal and X-ray-diffraction analyses indicated that the temperatures required to form the various compounds were lower than those necessary to form the compounds by conventional solid-state reactions and comparable to those required with use of organometallic based sol-gel methods. Temperatures of formation could be further reduced by addition of ascorbic acid to the sols.

Preparation of PZT Ferroelectric Thin Films by Sol-Gel Process

2012 ◽  
Vol 204-208 ◽  
pp. 4207-4210 ◽  
Author(s):  
Yu Fei You ◽  
C. H. Xu ◽  
Jun Peng Wang ◽  
Yu Liang Liu ◽  
Jin Feng Xiao ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pzt Ceramics ◽  
X Ray ◽  
Pzt Film ◽  
Sol Gel Process ◽  
Pzt Films ◽  
Pzt Ferroelectric Thin Films ◽  
Electronic Microscope

Sol-gel method is used for the formation of Pb(Zr0.63Ti0.37)O3(PZT) thin films. The initial films were formed with spin coating sol solution on silicon wafer and drying coated wet sol film at 300°C for 5min. This process was repeated for 1-4 times to obtain 4 initial films with different thicknesses. 4 initial films were annealed at 500°C for 2h to obtain PZT ceramics films. The morphologies of the surface and cross-section of PZT films were observed with a scanning electronic microscope (SEM). The phase structures of PZT films were analyzed using an X-ray diffraction meter (XRD). Experimental results show that PZT film prepared by coating wet sol on silicon once can be high smooth and compact film.

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

Structural, Magnetic, and Electrical Properties of BiFe1-xMnxO3 Thin Films

2009 ◽  
Vol 1199 ◽  
Author(s):  
Danilo G Barrionuevo ◽  
Surinder P Singh ◽  
Maharaj S. Tomar
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Ion Concentration ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Sol Gel Process

AbstractWe synthesized BiFe1-xMnxO3 (BFMO) for various compositions by sol gel process and thin films were deposited by spin coating on platinum Pt/Ti/SiO2/Si substrates. X-ray diffraction shows all the diffraction planes corresponding to rhombohedrally distorted perovskite BiFeO3 structure. The absence of any impurity phase in the films suggests the incorporation Mn ion preferentially to Fe site in the structure for low concentration. Magnetic measurements reveal the formation of ferromagnetic phase at room temperature with increased Mn substitution. On the other hand, ferroelectric polarization decreases with increasing Mn ion concentration. Raman studies suggest the dopant induced structural distortion.

scholarly journals Resistive Switching Characteristics of HfO2 Thin Films on Mica Substrates Prepared by Sol-Gel Process

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1124 ◽  
Author(s):  
Chao-Feng Liu ◽  
Xin-Gui Tang ◽  
Lun-Quan Wang ◽  
Hui Tang ◽  
Yan-Ping Jiang ◽  
...  
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Random Access ◽  
High Resistance State ◽  
X Ray ◽  
Low Resistance ◽  
Sol Gel Process ◽  
Resistance State

The resistive switching (RS) characteristics of flexible films deposited on mica substrates have rarely been reported upon, especially flexible HfO2 films. A novel flexible Au/HfO2/Pt/mica resistive random access memory device was prepared by a sol-gel process, and a Au/HfO2/Pt/Ti/SiO2/Si (100) device was also prepared for comparison. The HfO2 thin films were grown into the monoclinic phase by the proper annealing process at 700 °C, demonstrated by grazing-incidence X-ray diffraction patterns. The ratio of high/low resistance (off/on) reached 1000 and 50 for the two devices, respectively, being relatively stable for the former but not for the latter. The great difference in ratios for the two devices may have been caused by different concentrations of the oxygen defect obtained by the X-ray photoelectron spectroscopy spectra indicating composition and chemical state of the HfO2 thin films. The conduction mechanism was dominated by Ohm’s law in the low resistance state, while in high resistance state, Ohmic conduction, space charge limited conduction (SCLC), and trap-filled SCLC conducted together.

Properties of SiO2CuOx Films for Nitrogen Dioxide Detection

2013 ◽  
Vol 834-836 ◽  
pp. 112-116 ◽  
Author(s):  
Tatiana Myasoedova ◽  
G.E. Yalovega ◽  
V.V. Petrov ◽  
O.V. Zabluda ◽  
V.A. Shmatko ◽  
...  
Keyword(s):  
Thin Films ◽  
Nitrogen Dioxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Operating Temperatures

SiOxCuOythin films were prepared by the deposition on to the Si/SiO2substrates from the alcoholic solutions employing the sol-gel technique. The various analytic techniques were applied to characterize structure and properties of the films under study . The both X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies showed the presence CuO as well as CuO2phases and formation of a dual-oxide CuSiO3with the average crystallites sizes of 35-50 nm. The conductance of the films was rather sensitive to the presence of 1-20 ppm NO2concentration at the operating temperatures in the range of 20–200◦C.

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