Formation of multicomponent matrix metal oxide films in anodic alumina matrixes by chemical deposition

Zakhlebayeva

Таратын

et al. 2022

Sensors

This work presents and discusses the design of an efficient gas sensor, as well as the technological process of its fabrication. The optimal dimensions of the different sensor elements including their deformation were determined considering the geometric modeling and the calculated moduli of the elasticity and thermal conductivity coefficients. Multicomponent SnxBikMoyOz thin films were prepared by ionic layering on an anodic alumina membrane and were used as gas-sensitive layers in the sensor design. The resistance of the SnxBikMoyOz nanostructured film at temperatures up to 150 °C exceeded 106 Ohm but decreased to 104 Ohm at 550 °C in air. The sensitivity of the SnxBikMoyOz composite to concentrations of 5 and 40 ppm H2 at 250 °C (10 mW) was determined to be 0.22 and 0.40, respectively.

Section: Methodsmentioning

confidence: 99%

A Micropowered Chemoresistive Sensor Based on a Thin Alumina Nanoporous Membrane and SnxBikMoyOz Nanocomposite

Zakhlebayeva

Таратын

et al. 2022

Sensors

“…First, the CNTs suspension (1%) in propylene carbonate (Cnano Technology Limited Company) was sprayed on the NAAM‐defatted surface at the rate of 1 mL cm −2 . Then, the prepared composites were dried in air at T = 313 K for 1 h. The metal oxide systems of Sn x Mo y O z were formed by electrophoretic deposition of molybdenum and tin hydroxides . The Sn(OH) 2 films were prepared by electrophoretic deposition on NAAM from an aqueous solution of K 2 [Sn(OH) 4 ] (0.01 mol dm −3 ; pH = 8) at a field potential of V = 50 V, current frequency of f = 50 Hz, and interelectrode spacing of h = 200 mm.…”

Section: Methodsmentioning

confidence: 99%

“…Among the technological methods of film deposition, liquid‐phase methods occupy an increasingly significant position as they are less expensive in comparison with gas‐phase high‐temperature or vacuum processes . The most suitable and effective chemical methods for the formation of metal oxide films with a controlled composition and properties on nanoporous matrices are the electrophoretic layer‐by‐layer deposition, the ion layer deposition, the sol–gel method, and drop method using the aqueuos salts solutions . The electrophysical, chemosensitive, and magnetic characteristics of such composite films are related to their structural ordering, which is determined by the presence of the regularity of the arrangement of elementary crystallites .…”

Section: Introductionmentioning

confidence: 99%

Functional Multicomponent Metal Oxide Films Based on Sr, Sn, Fe, and Mo in the Anodic Alumina Matrices

Physica Status Solidi (b)

Zakhlebayeva

Lazavenka

et al. 2019

Low‐profile anodic alumina matrices of 1 μm thick with pore sizes of 105 and 160 nm are formed by two‐step anodizing of Al layers and are used as templates for the deposition of multicomponent metal oxide films on their surfaces. The metal oxide systems of Sr2FeMoO6−δ, FexMoyOz, and SnxMoyOz composites with carbon nanotubes are synthesized by electrophoretic deposition, sol–gel method, and drop method using aqueous salt solutions and are annealed at 373–473 K for 1–2 h and at 773–1123 K for 2–10 h. The morphology, microstructure, and composition of the porous alumina matrices with multicomponent metal oxides films are examined by scanning electron microscopy, energy‐dispersive X‐ray microanalysis, and X‐ray phase analysis. The use of anodic alumina matrices allows reducing the grain dimensions and gives uniformity to the microstructure and properties of the metal oxide films. The carbon nanotubes increase the working surface of the functional layer and its electrical conductivity. The variation in the synthesis conditions of deposited films and anodic alumina matrices configuration allows forming of different complex composition compounds with reproducible structure and properties.

“…In this case, the mixtures of oxides or combined oxide layers, for example, SnO 2 –WO 3 , Fe 2 O 3 –ZnO, and Bi 2 WO 6 are often used, which makes it possible to increase the sensitivity and selectivity of sensors, in turn improving their adsorption capacity and thermal stability [ 4 , 7 , 8 ]. The nanostructuring of thin films [ 9 , 10 ], the creation of regular arrays of nanostructures [ 11 ], as well as the formation of multicomponent metal oxide films [ 12 ] can significantly increase the functional characteristics of sensor microsystems created on their basis. At present, the well-known forming methods of nanostructured metal oxide films, using templates of nanoporous anodic alumina (NAA) [ 13 , 14 , 15 ], such as chemical deposition, electrophoretic deposition, and citrate-gel method [ 12 , 16 , 17 ], are already developed.…”

Section: Introductionmentioning

confidence: 99%

Spatially Ordered Matrix of Nanostructured Tin–Tungsten Oxides Nanocomposites Formed by Ionic Layer Deposition for Gas Sensing

Bogomazova

Taleb

et al. 2021

Sensors

The process of layer-by-layer ionic deposition of tin-tungsten oxide films on smooth silicon substrates and nanoporous anodic alumina matrices has been studied. To achieve the film deposition, solutions containing cationic SnF2 or SnCl2 and anionic Na2WO4 or (NH4)2O·WO3 precursors have been used. The effect of the solution compositions on the films deposition rates, morphology, composition, and properties was investigated. Possible mechanisms of tin-tungsten oxide films deposition into the pores and on the surface of anodic alumina are discussed. The electro-physical and gas-sensitive properties of nanostructured SnxWyOz films have been investigated. The prepared nanocomposites exhibit stable semiconductor properties characterized by high resistance and low temperature coefficient of electrical resistance of about 1.6 × 10−3 K−1. The sensitivity of the SnxWyOz films to 2 and 10 ppm concentrations of ammonia at 523 K was 0.35 and 1.17, respectively. At concentrations of 1 and 2 ppm of nitrogen dioxide, the sensitivity was 0.48 and 1.4, respectively, at a temperature of 473 K. At the temperature of 573 K, the sensitivity of 1.3 was obtained for 100 ppm of ethanol. The prepared nanostructured tin-tungsten oxide films showed promising gas-sensitivity, which makes them a good candidate for the manufacturing of gas sensors with high sensitivity and low power consumption.