A solution was synthesized in a system ZrO2-CeO2 by sol-gel synthesis and deposited by the immersion method. The pretreated Nb substrate was treated with sulfuric acid and absolute alcohol solutions. Layering was in three stages. The sample was heat treated at 500°C. The obtained results are characterized by XRD, XPS, CEM analyzes.
In view of the practical applications of the piezoelectric ceramics produced from barium titanate (BaTiO3) and barium stannate (BaSnO3), (the BT-BS system), the dielectric behavior of such materials was studied. The starting components (powder of both BaTiO3 and BaSnO3) were synthesizedand structurally characterized in аdvance. Bulk samples of BT-BS (formed as tablets with addition of PVA plasticizer) were prepared using the sol-gel method by varying the BT-BS composition percentage. The samples were characterized by complex electrical impedance spectroscopy and dielectric spectroscopy in the frequency range from 0.1 Hz to 1 MHz. As compared to BaTiO3, an increase with at least 50 % was measured for the value of the room-temperature dielectric constant (e′ – the real part of the dielectric permittivity) of the BT-BS samples containing 15 wt% BaSnO3. In contrast, the 50 wt% content of BaSnO3 led to a decrease of ′ value of BT-BS by a factor of 3.5, due to relatively low e′ value of BaSnO3. Analyses of the frequency spectra of complex electrical impedance and complex dielectric permittivity revealed the dielectric relaxational behavior of the BaTiO3+BaSnO3 system. The results obtained for ′ of BT-BS dielectrics as a function of the temperature were correlated with the data from structural studies. In particular, a specific enhancement of e′ was observed in temperature range around 120C for the BT-BS samples containing 15 wt% BaSnO3. Corresponding conclusions were done. The effects observed show that the synthesized BaTiO3-BaSnO3 ceramics are promising materials for piezoelectric and dielectric applications, e.g., in energy storage devices.
The aim of the present work is to study the characteristics and conditions of obtaining thin films in the BaTiO3–BaSnO3 system, deposited by the sol-gel method on monolithic multilayer samples. In laboratory conditions, the structure, phase composition, micromorphology, electrophysical parameters of the prepared experimental samples were studied. The existing possibilities for optimizing the applied technological regime for the synthesis and surface deposition of thin-layer coatings with set characteristics have been analyzed.
Dip coating is a common liquid deposition technique used in research and also for industrial production to produce polymeric, hybrid, and inorganic thin films of controlled thickness. During liquid deposition, the substrate withdrawal rate allows, in principle, easy tuning of the deposited film thickness. However, experimentally, unexplained thickness irreproducibility or strong fluctuations of sol-gel films are often observed when coating large substrates, which is a critical problem for optical coatings such as anti-reflective/reflective coatings. In this study, we present improved coatings obtained by sol gel-like multilayer structures composed of ZrO2-Y2O3 coating. The phase composition and morphology were analyzed by X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) suitable for characterizing the surface properties of the obtained materials.
The present publication is aimed at obtaining a stable sol from ZrO2 stabilized with Y2O3. The substrate on which the layers are deposited was developed by a team from Russia and is intermetalite with a layered structure Nb30Ti/Al. Deposition was performed by spinning with a Spin Coater Ossila L2001A3. The deposition sequence of the layers lasts 30 seconds. The finished carrier is dried at 120°C in an oven. It is heated in a laboratory furnace at 350oC. The results were characterized by XRD and SEM analyzes.
The research is aimed at creating a target from Sn doped barium-titanate ceramics. A technological regulation for the preparation of test bodies from a material synthesized by a low-temperature sol-gel method has been developed. The physicochemical parameters of the samples were determined and the temperature dependence of the dielectric permittivity was monitored. Physicochemical characterization of the samples was performed by X-Ray diffraction (XRD). and scanning electron microscopy (SEM). The preparation of pure BaTiO3 cubic phase was established. The dielectric permittivity of Sn doped barium-titanate possesses a maximum value of 45000 at a Curie temperature- Tc 40oC.
In recent years, interest in the application and use of materials for supercapacitors for electric vehicles has grown significantly. The advantage of capacitor ceramics over other dielectric materials for producing supercapacitors is its environmental friendliness and high economic efficiency. This paper presents the results of a study of capacitor ceramics doped with Sn at different locations of the modifier (tin) in BaSnTiO3 and BaTiSnO3 crystal lattice. The influence of modifiers in low-temperature sol-gel synthesis was studied. The samples were annealed at 1000°C. The resulting phases were identified by X-ray phase analysis. Microscopic analysis was also performed.
The sol-gel process is a well-known and reliable process for obtaining materials and coatings of different structure and properties. An important feature of this method is the choice of starting precursors to obtain the desired compositions. The complexity of the technology is due to the difficult process control. For this purpose it is necessary to accurately calculate the stoichiometry to obtain the final phase. Thus, the sol-gel technology is widely used as in the production of coatings by immersion and spraying, aerogels and others. However, there are many other applications such as electronic materials that have not yet been well studied. In this study, after a brief explanation of the process, some of the most important applications are considered.
The research in this article focuses on the synthesis of Ce donated BaTiO3 needed to make a target for magnetron sputtering. Synthesis is BaTiO3 by sol-gel method with a certain concentration of a modifying additive of Ce. The process of the sol-gel method is considered and the obtained results are characterized. Additional termal treatment of the obtained samples was performed at TOC = 900OC in a muffle furnace in Ar / H2 medium and in a laboratory furnace in air. Physicochemical methods by XRD analysis and Raman spectroscopy were used to characterize the results obtained
Zirconium dioxide-titanium dioxide coatings were obtained by sol-gel method on stainless steel plates. The samples were treated at three Zirconium dioxide-titanium dioxide coatings were obtained by sol-gel method on stainless steel plates. The samples were treated at three temperatures 300, 400 and 500oC. The morphology and chemical surface composition were examined by Scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), while the phase composition was examined by X-ray diffraction analyses (XRD). The corrosion resistance was evaluated by weight loss measurements in NaCl medium. The coatings are possess relatively smooth surface with some microcracks. After corrosion test the coatings treated at 500oC, keep their surface structure without visible signs of corrosion and thecorrosion tests revealed zero mass loss. The good protective properties of these coatings could be attributed to (i) amorphous structure, leading to deterioration of the ion and electron conduction of the films and (ii) probably increased density after the thermal treatment
Three types of oxide sol gel coatings: TiO2, CeO2 and TiO2/CeO2 composite were deposited by sol gel method on stainless steel and carbon steel. The morphology was examined by means of Scanning electron microscopy (SEM). X-ray diffraction analyses (XRD) were applied to investigate the phase composition. The corrosion resistances of the coatings were studied by evaluation of the weight loss in NaCl medium for 1200 hours. The surface of the TiO2 samples were relatively dense with a few surface nanocrystals and after tests does not shown any signs of corrosion. Тhe composite TiO2/CeO2 samples possess deep cracks which evidently favor the attacks in corrosion medium. Ceria and titania coatings deposited on stainless steel have zero weight loss in corrosive medium. The TiO2 coatings could also effective protect carbon steel, while the TiO2/CeO2 and CeO2 coatings exhibited lower corrosion resistance.
Titanium dioxide coatings and zirconium dioxide were deposited on SiO2 underlayers by sol-gel method on stainless steel plates. The samples were treated at two different temperatures (500 and 700oC) in air. The morphology was examined by means of Scanning electron microscopy (SEM) and the phase composition by X-ray diffraction analyses. The corrosion resistance of the coatings were examined by evaluation of the weight loss in NaCl medium. The TiO2/SiO2 coatings possess relatively smooth surface with some crystallites on the surface, while ZrO2/SiO2 coatings are not so smooth. After treatment at higher temperature the ZrO2/SiO2 coatings become rougher. The weight loss measurement have proved that the TiO2/SiO2 coatings exhibit higher corrosion resistance in comparison to ZrO2/SiO2 coatings. The TiO2/SiO2 coatings, treated at 500oC after the corrosion test retain their characteristic grain structure without any cracks and other defects. Similar is the structure of these coatings, treated at 700oC. The better protective properties of TiO2/SiO2 could be attributed to their amorphous dense structure.