Optical Switches Based on Vanadium Dioxide Films Grown By The Sol-Gel Process

1990 ◽  
Vol 180 ◽  
Author(s):  
Richard S. Potember ◽  
Kenneth R. Speck
Keyword(s):  
Transition Metal Oxides ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Optical Switches ◽  
Glass Slides ◽  
Sol Gel Process ◽  
Metal Phase Transition ◽  
Isopropanol Solution ◽  
High Degree ◽  
Vanadium Dioxide Thin Films

ABSTRACTVanadium dioxide thin films have been grown from vanadium tetrakis (t-butoxide) by the sol-gel process. A new method for the synthesis of the vanadium precursor was also developed. Films were deposited by dipcoating glass slides from an isopropanol solution, followed by post-deposition annealing of the films at 600°C under nitrogen. The properties of these films, to a high degree, were a function of crystalline boundaries and crystalline grain size. These gel-derived VO2 films undergo a reversible semiconductor-to-metal phase transition near 72°C, exhibiting characteristic resistive and spectral switching comparable with near stoichiometric VO2 films prepared on non-crystalline substrates by other techniques. Films were doped with hexavalent transition metal oxides to demonstrate lowering of the transition of the transition temperature.

Vanadium Dioxide Films Grown from Vanadium Tetrakis(t-Butoxide) by the Sol-Gel Process

1988 ◽  
Vol 121 ◽  
Author(s):  
K. R. Speck ◽  
H. S-W. Hu ◽  
R. A. Murphy ◽  
R. S. Potember
Keyword(s):  
Transition Metal Oxides ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Preparation Conditions ◽  
Glass Slides ◽  
Sol Gel Process ◽  
Metal Phase Transition ◽  
Isopropanol Solution ◽  
High Degree ◽  
Vanadium Dioxide Thin Films

ABSTRACTVanadium dioxide thin films have been grown from vanadium tetrakis (t-butoxide) by the sol-gel process. A new method for the synthesis of the vanadium precursor was developed. Films were deposited by dipcoating glass slides from an isopropanol solution, followed by post-deposition annealing of the films at 600 °C under nitrogen. The properties of these films, to a high degree, were a function of the preparation conditions. These gel-derived VO2 films undergo a reversible semiconductor-to-metal phase transition near 72 °C, exhibiting characteristic resistive and spectral switching comparable with near stoichiometric VO2 films prepared on non-crystalline substrates by other techniques. Paralleling the investigation of pure VO2, films were doped with hexavalent transition metal oxides to demonstrate lowering of the transition temperature.

Study on the Grain Size of Vanadium Dioxide Thin Films using Sol-gel Spin Coating Method

2018 ◽  
Author(s):  
Ibrahim Mohd Yazid ◽  
Muhammad Hazim Raselan ◽  
Shafinaz Sobihana Shariffudin ◽  
Puteri Sarah Mohamad Saad ◽  
Sukreen Hana ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Vanadium Dioxide ◽  
Spin Coating ◽  
Sol Gel ◽  
Spin Coating Method ◽  
Coating Method ◽  
Vanadium Dioxide 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.

scholarly journals Co-Doped LaMnO3 Perovskite Structure Nanoparticles as a Bifunctional Electrocatalysts for Oxygen Reduction/Evolution Reactions

2020 ◽  
Vol 9 (7) ◽  
pp. 1060-1064
Keyword(s):  
Transition Metal Oxides ◽  
Perovskite Structure ◽  
Single Phase ◽  
Sol Gel ◽  
Perovskite Oxide ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Bifunctional Electrocatalysts ◽  
Sol Gel Process ◽  
Perovskite Nanoparticles

Current paper, we have examined lanthanum manganese cobalt (LaMn1-xCoxO3 ) perovskite nanoparticles synthesized by utilizing the sol-gel process and following calcinated at 450 °C for 1h and 900 °C for 7h, respectively. The fabricated alloys show single-phase perovskite structure is an order of LaMn1-xCoxO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1). The synthesized LaMn1-xCoxO3 perovskite oxide nanoparticles have the crystal structure, and powder morphology properties were investigated by X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM), respectively. The perovskite structure has been shown to be particularly effective for the catalytic reactions of ORR and OER in alkaline medium. The merged valance transition metal oxides are bifunctional electrocatalysts which give rise to potential candidates, the electrochemical functioning of the LaMn1-xCoxO3 catalyst was entirely investigated. All compounds of ORR polarization curves show that the four-electron pathway, which results in KouteckyLevich is compatible with these perovskite structures. Current work, we describe B-site extend adding of Co ratio into perovskite structure is an appropriate strategy to increase ORR and OER electrocatalytic performance for application in metal-air batteries

Organic–inorganic sol-gel thick films for humidity barriers

2008 ◽  
Vol 23 (8) ◽  
pp. 2084-2090 ◽  
Author(s):  
Andrei Jitianu ◽  
Glenn Amatucci ◽  
Lisa C. Klein
Keyword(s):  
Contact Angle ◽  
Thick Films ◽  
Sol Gel ◽  
Attenuated Total Reflection ◽  
Inorganic Materials ◽  
Angle Measurements ◽  
Glass Slides ◽  
Contact Angle Measurements ◽  
Sol Gel Process ◽  
Poly Ethylene

Hybrid thick films were deposited on Surlyn, a copolymer of poly(ethylene- co-methacrylic acid) and a common adhesion film for metal surfaces. Hybrid organic–inorganic materials were prepared by a sol-gel process. Methyltriethoxysilane (MTES) with tetraethoxysilane (TEOS), phenyltriethoxysilane (PhTES) with TEOS, and methyltrimethoxysilane (MTMS) with tetramethoxysilane (TMOS) were investigated. The inorganic component was selected to form the network for the film, while the organic component was selected to repel water and fill porosity. The films were deposited on Surlyn and on glass slides. The properties of the films were investigated using attenuated total reflection Fourier transform infrared (FTIR) and Raman spectroscopy. Contact-angle measurements indicated that the contact angle increased from ∼76.5° for Surlyn alone to ∼89.6° for Surlyn coated with MTES.

Thermochromic characteristics of WO3-doped vanadium dioxide thin films prepared by sol–gel method

2012 ◽  
Vol 38 ◽  
pp. S589-S593 ◽  
Author(s):  
Jeong-Ho Cho ◽  
Young-Jun Byun ◽  
Jin-Ho Kim ◽  
Young-Jin Lee ◽  
Young-Hun Jeong ◽  
...  
Keyword(s):  
Thin Films ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Vanadium Dioxide Thin Films

scholarly journals The Effect of Alkali Metal (Na, K) Doping on Thermochromic Properties of VO2 Films

MRS Advances ◽  
2018 ◽  
Vol 3 (32) ◽  
pp. 1863-1869 ◽  
Author(s):  
Işıl Top ◽  
Johannes Schläfer ◽  
Russell Binions ◽  
Ioannis Papakonstantinou ◽  
Sriluxmi Srimurugananthan ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Alkali Metal ◽  
Vanadium Dioxide ◽  
Sol Gel ◽  
Critical Transition Temperature ◽  
Low Temperature Annealing ◽  
Thermochromic Properties ◽  
Metal Doped ◽  
Sodium And Potassium ◽  
Vanadium Dioxide Thin Films

ABSTRACT:This work reports the synthesis of undoped and alkali metal doped thermochromic vanadium dioxide thin films by sol-gel spin coating and subsequent low-temperature annealing at 450 °C in N2-H2 atmosphere. The effect of sodium and potassium on the phase transition temperature as well as on the solar modulations were investigated. A dopant concentration of 0.3 at% resulted in a reduction of the critical transition temperature (Tc) from 62 °C to 57 °C and 47 °C for the sodium and potassium doped films, respectively. Moreover, both dopants improved the solar modulations (ΔTsol) of the undoped VO2 films from 3.81 to 9.44 and 5.43 %, respectively.

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